Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

42 files changed, 13199 insertions, 0 deletions

diff --git a/image/decoders/EXIF.cpp b/image/decoders/EXIF.cpp
new file mode 100644
index 0000000000..97563248c7
--- /dev/null
+++ b/image/decoders/EXIF.cpp
@@ -0,0 +1,519 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "EXIF.h"
+
+#include "mozilla/EndianUtils.h"
+#include "mozilla/StaticPrefs_image.h"
+
+namespace mozilla::image {
+
+// Section references in this file refer to the EXIF v2.3 standard, also known
+// as CIPA DC-008-Translation-2010.
+
+// See Section 4.6.4, Table 4.
+// Typesafe enums are intentionally not used here since we're comparing to raw
+// integers produced by parsing.
+enum class EXIFTag : uint16_t {
+  Orientation = 0x112,
+  XResolution = 0x11a,
+  YResolution = 0x11b,
+  PixelXDimension = 0xa002,
+  PixelYDimension = 0xa003,
+  ResolutionUnit = 0x128,
+  IFDPointer = 0x8769,
+};
+
+// See Section 4.6.2.
+enum EXIFType {
+  ByteType = 1,
+  ASCIIType = 2,
+  ShortType = 3,
+  LongType = 4,
+  RationalType = 5,
+  UndefinedType = 7,
+  SignedLongType = 9,
+  SignedRational = 10,
+};
+
+static const char* EXIFHeader = "Exif\0\0";
+static const uint32_t EXIFHeaderLength = 6;
+static const uint32_t TIFFHeaderStart = EXIFHeaderLength;
+
+struct ParsedEXIFData {
+  Orientation orientation;
+  Maybe<float> resolutionX;
+  Maybe<float> resolutionY;
+  Maybe<uint32_t> pixelXDimension;
+  Maybe<uint32_t> pixelYDimension;
+  Maybe<ResolutionUnit> resolutionUnit;
+};
+
+static float ToDppx(float aResolution, ResolutionUnit aUnit) {
+  constexpr float kPointsPerInch = 72.0f;
+  constexpr float kPointsPerCm = 1.0f / 2.54f;
+  switch (aUnit) {
+    case ResolutionUnit::Dpi:
+      return aResolution / kPointsPerInch;
+    case ResolutionUnit::Dpcm:
+      return aResolution / kPointsPerCm;
+  }
+  MOZ_CRASH("Unknown resolution unit?");
+}
+
+static Resolution ResolutionFromParsedData(const ParsedEXIFData& aData,
+                                           const gfx::IntSize& aRealImageSize) {
+  if (!aData.resolutionUnit || !aData.resolutionX || !aData.resolutionY) {
+    return {};
+  }
+
+  Resolution resolution{ToDppx(*aData.resolutionX, *aData.resolutionUnit),
+                        ToDppx(*aData.resolutionY, *aData.resolutionUnit)};
+
+  if (StaticPrefs::image_exif_density_correction_sanity_check_enabled()) {
+    if (!aData.pixelXDimension || !aData.pixelYDimension) {
+      return {};
+    }
+
+    const gfx::IntSize exifSize(*aData.pixelXDimension, *aData.pixelYDimension);
+
+    gfx::IntSize scaledSize = aRealImageSize;
+    resolution.ApplyTo(scaledSize.width, scaledSize.height);
+
+    if (exifSize != scaledSize) {
+      return {};
+    }
+  }
+
+  return resolution;
+}
+
+/////////////////////////////////////////////////////////////
+// Parse EXIF data, typically found in a JPEG's APP1 segment.
+/////////////////////////////////////////////////////////////
+EXIFData EXIFParser::ParseEXIF(const uint8_t* aData, const uint32_t aLength,
+                               const gfx::IntSize& aRealImageSize) {
+  if (!Initialize(aData, aLength)) {
+    return EXIFData();
+  }
+
+  if (!ParseEXIFHeader()) {
+    return EXIFData();
+  }
+
+  uint32_t offsetIFD;
+  if (!ParseTIFFHeader(offsetIFD)) {
+    return EXIFData();
+  }
+
+  JumpTo(offsetIFD);
+
+  ParsedEXIFData data;
+  ParseIFD(data);
+
+  return EXIFData{data.orientation,
+                  ResolutionFromParsedData(data, aRealImageSize)};
+}
+
+/////////////////////////////////////////////////////////
+// Parse the EXIF header. (Section 4.7.2, Figure 30)
+/////////////////////////////////////////////////////////
+bool EXIFParser::ParseEXIFHeader() {
+  return MatchString(EXIFHeader, EXIFHeaderLength);
+}
+
+/////////////////////////////////////////////////////////
+// Parse the TIFF header. (Section 4.5.2, Table 1)
+/////////////////////////////////////////////////////////
+bool EXIFParser::ParseTIFFHeader(uint32_t& aIFD0OffsetOut) {
+  // Determine byte order.
+  if (MatchString("MM\0*", 4)) {
+    mByteOrder = ByteOrder::BigEndian;
+  } else if (MatchString("II*\0", 4)) {
+    mByteOrder = ByteOrder::LittleEndian;
+  } else {
+    return false;
+  }
+
+  // Determine offset of the 0th IFD. (It shouldn't be greater than 64k, which
+  // is the maximum size of the entry APP1 segment.)
+  uint32_t ifd0Offset;
+  if (!ReadUInt32(ifd0Offset) || ifd0Offset > 64 * 1024) {
+    return false;
+  }
+
+  // The IFD offset is relative to the beginning of the TIFF header, which
+  // begins after the EXIF header, so we need to increase the offset
+  // appropriately.
+  aIFD0OffsetOut = ifd0Offset + TIFFHeaderStart;
+  return true;
+}
+
+// An arbitrary limit on the amount of pointers that we'll chase, to prevent bad
+// inputs getting us stuck.
+constexpr uint32_t kMaxEXIFDepth = 16;
+
+/////////////////////////////////////////////////////////
+// Parse the entries in IFD0. (Section 4.6.2)
+/////////////////////////////////////////////////////////
+void EXIFParser::ParseIFD(ParsedEXIFData& aData, uint32_t aDepth) {
+  if (NS_WARN_IF(aDepth > kMaxEXIFDepth)) {
+    return;
+  }
+
+  uint16_t entryCount;
+  if (!ReadUInt16(entryCount)) {
+    return;
+  }
+
+  for (uint16_t entry = 0; entry < entryCount; ++entry) {
+    // Read the fields of the 12-byte entry.
+    uint16_t tag;
+    if (!ReadUInt16(tag)) {
+      return;
+    }
+
+    uint16_t type;
+    if (!ReadUInt16(type)) {
+      return;
+    }
+
+    uint32_t count;
+    if (!ReadUInt32(count)) {
+      return;
+    }
+
+    switch (EXIFTag(tag)) {
+      case EXIFTag::Orientation:
+        // We should have an orientation value here; go ahead and parse it.
+        if (!ParseOrientation(type, count, aData.orientation)) {
+          return;
+        }
+        break;
+      case EXIFTag::ResolutionUnit:
+        if (!ParseResolutionUnit(type, count, aData.resolutionUnit)) {
+          return;
+        }
+        break;
+      case EXIFTag::XResolution:
+        if (!ParseResolution(type, count, aData.resolutionX)) {
+          return;
+        }
+        break;
+      case EXIFTag::YResolution:
+        if (!ParseResolution(type, count, aData.resolutionY)) {
+          return;
+        }
+        break;
+      case EXIFTag::PixelXDimension:
+        if (!ParseDimension(type, count, aData.pixelXDimension)) {
+          return;
+        }
+        break;
+      case EXIFTag::PixelYDimension:
+        if (!ParseDimension(type, count, aData.pixelYDimension)) {
+          return;
+        }
+        break;
+      case EXIFTag::IFDPointer: {
+        uint32_t offset;
+        if (!ReadUInt32(offset)) {
+          return;
+        }
+
+        ScopedJump jump(*this, offset + TIFFHeaderStart);
+        ParseIFD(aData, aDepth + 1);
+        break;
+      }
+
+      default:
+        Advance(4);
+        break;
+    }
+  }
+}
+
+bool EXIFParser::ReadRational(float& aOut) {
+  // Values larger than 4 bytes (like rationals) are specified as an offset into
+  // the TIFF header.
+  uint32_t valueOffset;
+  if (!ReadUInt32(valueOffset)) {
+    return false;
+  }
+  ScopedJump jumpToHeader(*this, valueOffset + TIFFHeaderStart);
+  uint32_t numerator;
+  if (!ReadUInt32(numerator)) {
+    return false;
+  }
+  uint32_t denominator;
+  if (!ReadUInt32(denominator)) {
+    return false;
+  }
+  if (denominator == 0) {
+    return false;
+  }
+  aOut = float(numerator) / float(denominator);
+  return true;
+}
+
+bool EXIFParser::ParseResolution(uint16_t aType, uint32_t aCount,
+                                 Maybe<float>& aOut) {
+  if (!StaticPrefs::image_exif_density_correction_enabled()) {
+    Advance(4);
+    return true;
+  }
+  if (aType != RationalType || aCount != 1) {
+    return false;
+  }
+  float value;
+  if (!ReadRational(value)) {
+    return false;
+  }
+  if (value == 0.0f) {
+    return false;
+  }
+  aOut = Some(value);
+  return true;
+}
+
+bool EXIFParser::ParseDimension(uint16_t aType, uint32_t aCount,
+                                Maybe<uint32_t>& aOut) {
+  if (!StaticPrefs::image_exif_density_correction_enabled()) {
+    Advance(4);
+    return true;
+  }
+
+  if (aCount != 1) {
+    return false;
+  }
+
+  switch (aType) {
+    case ShortType: {
+      uint16_t value;
+      if (!ReadUInt16(value)) {
+        return false;
+      }
+      aOut = Some(value);
+      Advance(2);
+      break;
+    }
+    case LongType: {
+      uint32_t value;
+      if (!ReadUInt32(value)) {
+        return false;
+      }
+      aOut = Some(value);
+      break;
+    }
+    default:
+      return false;
+  }
+  return true;
+}
+
+bool EXIFParser::ParseResolutionUnit(uint16_t aType, uint32_t aCount,
+                                     Maybe<ResolutionUnit>& aOut) {
+  if (!StaticPrefs::image_exif_density_correction_enabled()) {
+    Advance(4);
+    return true;
+  }
+  if (aType != ShortType || aCount != 1) {
+    return false;
+  }
+  uint16_t value;
+  if (!ReadUInt16(value)) {
+    return false;
+  }
+  switch (value) {
+    case 2:
+      aOut = Some(ResolutionUnit::Dpi);
+      break;
+    case 3:
+      aOut = Some(ResolutionUnit::Dpcm);
+      break;
+    default:
+      return false;
+  }
+
+  // This is a 32-bit field, but the unit value only occupies the first 16 bits.
+  // We need to advance another 16 bits to consume the entire field.
+  Advance(2);
+  return true;
+}
+
+bool EXIFParser::ParseOrientation(uint16_t aType, uint32_t aCount,
+                                  Orientation& aOut) {
+  // Sanity check the type and count.
+  if (aType != ShortType || aCount != 1) {
+    return false;
+  }
+
+  uint16_t value;
+  if (!ReadUInt16(value)) {
+    return false;
+  }
+
+  switch (value) {
+    case 1:
+      aOut = Orientation(Angle::D0, Flip::Unflipped);
+      break;
+    case 2:
+      aOut = Orientation(Angle::D0, Flip::Horizontal);
+      break;
+    case 3:
+      aOut = Orientation(Angle::D180, Flip::Unflipped);
+      break;
+    case 4:
+      aOut = Orientation(Angle::D180, Flip::Horizontal);
+      break;
+    case 5:
+      aOut = Orientation(Angle::D90, Flip::Horizontal);
+      break;
+    case 6:
+      aOut = Orientation(Angle::D90, Flip::Unflipped);
+      break;
+    case 7:
+      aOut = Orientation(Angle::D270, Flip::Horizontal);
+      break;
+    case 8:
+      aOut = Orientation(Angle::D270, Flip::Unflipped);
+      break;
+    default:
+      return false;
+  }
+
+  // This is a 32-bit field, but the orientation value only occupies the first
+  // 16 bits. We need to advance another 16 bits to consume the entire field.
+  Advance(2);
+  return true;
+}
+
+bool EXIFParser::Initialize(const uint8_t* aData, const uint32_t aLength) {
+  if (aData == nullptr) {
+    return false;
+  }
+
+  // An APP1 segment larger than 64k violates the JPEG standard.
+  if (aLength > 64 * 1024) {
+    return false;
+  }
+
+  mStart = mCurrent = aData;
+  mLength = mRemainingLength = aLength;
+  mByteOrder = ByteOrder::Unknown;
+  return true;
+}
+
+void EXIFParser::Advance(const uint32_t aDistance) {
+  if (mRemainingLength >= aDistance) {
+    mCurrent += aDistance;
+    mRemainingLength -= aDistance;
+  } else {
+    mCurrent = mStart;
+    mRemainingLength = 0;
+  }
+}
+
+void EXIFParser::JumpTo(const uint32_t aOffset) {
+  if (mLength >= aOffset) {
+    mCurrent = mStart + aOffset;
+    mRemainingLength = mLength - aOffset;
+  } else {
+    mCurrent = mStart;
+    mRemainingLength = 0;
+  }
+}
+
+bool EXIFParser::MatchString(const char* aString, const uint32_t aLength) {
+  if (mRemainingLength < aLength) {
+    return false;
+  }
+
+  for (uint32_t i = 0; i < aLength; ++i) {
+    if (mCurrent[i] != aString[i]) {
+      return false;
+    }
+  }
+
+  Advance(aLength);
+  return true;
+}
+
+bool EXIFParser::MatchUInt16(const uint16_t aValue) {
+  if (mRemainingLength < 2) {
+    return false;
+  }
+
+  bool matched;
+  switch (mByteOrder) {
+    case ByteOrder::LittleEndian:
+      matched = LittleEndian::readUint16(mCurrent) == aValue;
+      break;
+    case ByteOrder::BigEndian:
+      matched = BigEndian::readUint16(mCurrent) == aValue;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Should know the byte order by now");
+      matched = false;
+  }
+
+  if (matched) {
+    Advance(2);
+  }
+
+  return matched;
+}
+
+bool EXIFParser::ReadUInt16(uint16_t& aValue) {
+  if (mRemainingLength < 2) {
+    return false;
+  }
+
+  bool matched = true;
+  switch (mByteOrder) {
+    case ByteOrder::LittleEndian:
+      aValue = LittleEndian::readUint16(mCurrent);
+      break;
+    case ByteOrder::BigEndian:
+      aValue = BigEndian::readUint16(mCurrent);
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Should know the byte order by now");
+      matched = false;
+  }
+
+  if (matched) {
+    Advance(2);
+  }
+
+  return matched;
+}
+
+bool EXIFParser::ReadUInt32(uint32_t& aValue) {
+  if (mRemainingLength < 4) {
+    return false;
+  }
+
+  bool matched = true;
+  switch (mByteOrder) {
+    case ByteOrder::LittleEndian:
+      aValue = LittleEndian::readUint32(mCurrent);
+      break;
+    case ByteOrder::BigEndian:
+      aValue = BigEndian::readUint32(mCurrent);
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Should know the byte order by now");
+      matched = false;
+  }
+
+  if (matched) {
+    Advance(4);
+  }
+
+  return matched;
+}
+
+}  // namespace mozilla::image
diff --git a/image/decoders/EXIF.h b/image/decoders/EXIF.h
new file mode 100644
index 0000000000..eb23f8d537
--- /dev/null
+++ b/image/decoders/EXIF.h
@@ -0,0 +1,95 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_EXIF_h
+#define mozilla_image_decoders_EXIF_h
+
+#include <stdint.h>
+#include "nsDebug.h"
+
+#include "Orientation.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/image/Resolution.h"
+#include "mozilla/gfx/Point.h"
+
+namespace mozilla::image {
+
+enum class ByteOrder : uint8_t { Unknown, LittleEndian, BigEndian };
+
+struct EXIFData {
+  const Orientation orientation = Orientation();
+  const Resolution resolution = Resolution();
+};
+
+struct ParsedEXIFData;
+
+enum class ResolutionUnit : uint8_t {
+  Dpi,
+  Dpcm,
+};
+
+class EXIFParser {
+ public:
+  static EXIFData Parse(const uint8_t* aData, const uint32_t aLength,
+                        const gfx::IntSize& aRealImageSize) {
+    EXIFParser parser;
+    return parser.ParseEXIF(aData, aLength, aRealImageSize);
+  }
+
+ private:
+  EXIFParser()
+      : mStart(nullptr),
+        mCurrent(nullptr),
+        mLength(0),
+        mRemainingLength(0),
+        mByteOrder(ByteOrder::Unknown) {}
+
+  EXIFData ParseEXIF(const uint8_t* aData, const uint32_t aLength,
+                     const gfx::IntSize& aRealImageSize);
+  bool ParseEXIFHeader();
+  bool ParseTIFFHeader(uint32_t& aIFD0OffsetOut);
+
+  void ParseIFD(ParsedEXIFData&, uint32_t aDepth = 0);
+  bool ParseOrientation(uint16_t aType, uint32_t aCount, Orientation&);
+  bool ParseResolution(uint16_t aType, uint32_t aCount, Maybe<float>&);
+  bool ParseResolutionUnit(uint16_t aType, uint32_t aCount,
+                           Maybe<ResolutionUnit>&);
+  bool ParseDimension(uint16_t aType, uint32_t aCount, Maybe<uint32_t>&);
+
+  bool Initialize(const uint8_t* aData, const uint32_t aLength);
+  void Advance(const uint32_t aDistance);
+  void JumpTo(const uint32_t aOffset);
+
+  uint32_t CurrentOffset() const { return mCurrent - mStart; }
+
+  class ScopedJump {
+    EXIFParser& mParser;
+    uint32_t mOldOffset;
+
+   public:
+    ScopedJump(EXIFParser& aParser, uint32_t aOffset)
+        : mParser(aParser), mOldOffset(aParser.CurrentOffset()) {
+      mParser.JumpTo(aOffset);
+    }
+
+    ~ScopedJump() { mParser.JumpTo(mOldOffset); }
+  };
+
+  bool MatchString(const char* aString, const uint32_t aLength);
+  bool MatchUInt16(const uint16_t aValue);
+  bool ReadUInt16(uint16_t& aOut);
+  bool ReadUInt32(uint32_t& aOut);
+  bool ReadRational(float& aOut);
+
+  const uint8_t* mStart;
+  const uint8_t* mCurrent;
+  uint32_t mLength;
+  uint32_t mRemainingLength;
+  ByteOrder mByteOrder;
+};
+
+}  // namespace mozilla::image
+
+#endif  // mozilla_image_decoders_EXIF_h
diff --git a/image/decoders/GIF2.h b/image/decoders/GIF2.h
new file mode 100644
index 0000000000..c0c6bf0fde
--- /dev/null
+++ b/image/decoders/GIF2.h
@@ -0,0 +1,67 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_GIF2_H
+#define mozilla_image_decoders_GIF2_H
+
+#define MAX_LZW_BITS 12
+#define MAX_BITS 4097  // 2^MAX_LZW_BITS+1
+#define MAX_COLORS 256
+#define MIN_HOLD_SIZE 256
+
+enum { GIF_TRAILER = 0x3B };               // ';'
+enum { GIF_IMAGE_SEPARATOR = 0x2C };       // ','
+enum { GIF_EXTENSION_INTRODUCER = 0x21 };  // '!'
+enum { GIF_GRAPHIC_CONTROL_LABEL = 0xF9 };
+enum { GIF_APPLICATION_EXTENSION_LABEL = 0xFF };
+
+// A GIF decoder's state
+typedef struct gif_struct {
+  // LZW decoder state machine
+  uint8_t* stackp;  // Current stack pointer
+  int datasize;
+  int codesize;
+  int codemask;
+  int avail;  // Index of next available slot in dictionary
+  int oldcode;
+  uint8_t firstchar;
+  int bits;       // Number of unread bits in "datum"
+  int32_t datum;  // 32-bit input buffer
+
+  // Output state machine
+  int64_t pixels_remaining;  // Pixels remaining to be output.
+
+  // Parameters for image frame currently being decoded
+  int tpixel;                // Index of transparent pixel
+  int32_t disposal_method;   // Restore to background, leave in place, etc.
+  uint32_t* local_colormap;  // Per-image colormap
+  uint32_t local_colormap_buffer_size;  // Size of the buffer containing the
+                                        // local colormap.
+  int local_colormap_size;              // Size of local colormap array.
+  uint32_t delay_time;                  // Display time, in milliseconds,
+                                        // for this image in a multi-image GIF
+
+  // Global (multi-image) state
+  int version;           // Either 89 for GIF89 or 87 for GIF87
+  int32_t screen_width;  // Logical screen width & height
+  int32_t screen_height;
+  uint8_t global_colormap_depth;   // Depth of global colormap array
+  uint16_t global_colormap_count;  // Number of colors in global colormap
+  int images_decoded;              // Counts images for multi-part GIFs
+  int loop_count;  // Netscape specific extension block to control
+                   // the number of animation loops a GIF
+                   // renders.
+
+  bool is_transparent;  // TRUE, if tpixel is valid
+
+  uint16_t prefix[MAX_BITS];             // LZW decoding tables
+  uint32_t global_colormap[MAX_COLORS];  // Default colormap if local not
+                                         //   supplied
+  uint8_t suffix[MAX_BITS];              // LZW decoding tables
+  uint8_t stack[MAX_BITS];               // Base of LZW decoder stack
+
+} gif_struct;
+
+#endif  // mozilla_image_decoders_GIF2_H
diff --git a/image/decoders/iccjpeg.c b/image/decoders/iccjpeg.c
new file mode 100644
index 0000000000..6157fe8298
--- /dev/null
+++ b/image/decoders/iccjpeg.c
@@ -0,0 +1,184 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * iccjpeg.c
+ *
+ * This file provides code to read and write International Color Consortium
+ * (ICC) device profiles embedded in JFIF JPEG image files.  The ICC has
+ * defined a standard format for including such data in JPEG "APP2" markers.
+ * The code given here does not know anything about the internal structure
+ * of the ICC profile data; it just knows how to put the profile data into
+ * a JPEG file being written, or get it back out when reading.
+ *
+ * This code depends on new features added to the IJG JPEG library as of
+ * IJG release 6b; it will not compile or work with older IJG versions.
+ *
+ * NOTE: this code would need surgery to work on 16-bit-int machines
+ * with ICC profiles exceeding 64K bytes in size.  If you need to do that,
+ * change all the "unsigned int" variables to "INT32".  You'll also need
+ * to find a malloc() replacement that can allocate more than 64K.
+ */
+
+#include "iccjpeg.h"
+#include <stdlib.h> /* define malloc() */
+
+/*
+ * Since an ICC profile can be larger than the maximum size of a JPEG marker
+ * (64K), we need provisions to split it into multiple markers.  The format
+ * defined by the ICC specifies one or more APP2 markers containing the
+ * following data:
+ *      Identifying string      ASCII "ICC_PROFILE\0"  (12 bytes)
+ *      Marker sequence number  1 for first APP2, 2 for next, etc (1 byte)
+ *      Number of markers       Total number of APP2's used (1 byte)
+ *      Profile data            (remainder of APP2 data)
+ * Decoders should use the marker sequence numbers to reassemble the profile,
+ * rather than assuming that the APP2 markers appear in the correct sequence.
+ */
+
+#define ICC_MARKER (JPEG_APP0 + 2) /* JPEG marker code for ICC */
+#define ICC_OVERHEAD_LEN 14        /* size of non-profile data in APP2 */
+#define MAX_BYTES_IN_MARKER 65533  /* maximum data len of a JPEG marker */
+#define MAX_DATA_BYTES_IN_MARKER (MAX_BYTES_IN_MARKER - ICC_OVERHEAD_LEN)
+
+/*
+ * Prepare for reading an ICC profile
+ */
+
+void setup_read_icc_profile(j_decompress_ptr cinfo) {
+  /* Tell the library to keep any APP2 data it may find */
+  jpeg_save_markers(cinfo, ICC_MARKER, 0xFFFF);
+}
+
+/*
+ * Handy subroutine to test whether a saved marker is an ICC profile marker.
+ */
+
+static boolean marker_is_icc(jpeg_saved_marker_ptr marker) {
+  return marker->marker == ICC_MARKER &&
+         marker->data_length >= ICC_OVERHEAD_LEN &&
+         /* verify the identifying string */
+         GETJOCTET(marker->data[0]) == 0x49 &&
+         GETJOCTET(marker->data[1]) == 0x43 &&
+         GETJOCTET(marker->data[2]) == 0x43 &&
+         GETJOCTET(marker->data[3]) == 0x5F &&
+         GETJOCTET(marker->data[4]) == 0x50 &&
+         GETJOCTET(marker->data[5]) == 0x52 &&
+         GETJOCTET(marker->data[6]) == 0x4F &&
+         GETJOCTET(marker->data[7]) == 0x46 &&
+         GETJOCTET(marker->data[8]) == 0x49 &&
+         GETJOCTET(marker->data[9]) == 0x4C &&
+         GETJOCTET(marker->data[10]) == 0x45 &&
+         GETJOCTET(marker->data[11]) == 0x0;
+}
+
+/*
+ * See if there was an ICC profile in the JPEG file being read;
+ * if so, reassemble and return the profile data.
+ *
+ * TRUE is returned if an ICC profile was found, FALSE if not.
+ * If TRUE is returned, *icc_data_ptr is set to point to the
+ * returned data, and *icc_data_len is set to its length.
+ *
+ * IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
+ * and must be freed by the caller with free() when the caller no longer
+ * needs it.  (Alternatively, we could write this routine to use the
+ * IJG library's memory allocator, so that the data would be freed implicitly
+ * at jpeg_finish_decompress() time.  But it seems likely that many apps
+ * will prefer to have the data stick around after decompression finishes.)
+ *
+ * NOTE: if the file contains invalid ICC APP2 markers, we just silently
+ * return FALSE.  You might want to issue an error message instead.
+ */
+
+boolean read_icc_profile(j_decompress_ptr cinfo, JOCTET** icc_data_ptr,
+                         unsigned int* icc_data_len) {
+  jpeg_saved_marker_ptr marker;
+  int num_markers = 0;
+  int seq_no;
+  JOCTET* icc_data;
+  unsigned int total_length;
+#define MAX_SEQ_NO 255 /* sufficient since marker numbers are bytes */
+  char marker_present[MAX_SEQ_NO + 1];      /* 1 if marker found */
+  unsigned int data_length[MAX_SEQ_NO + 1]; /* size of profile data in marker */
+  unsigned int data_offset[MAX_SEQ_NO + 1]; /* offset for data in marker */
+
+  *icc_data_ptr = NULL; /* avoid confusion if FALSE return */
+  *icc_data_len = 0;
+
+  /* This first pass over the saved markers discovers whether there are
+   * any ICC markers and verifies the consistency of the marker numbering.
+   */
+
+  for (seq_no = 1; seq_no <= MAX_SEQ_NO; seq_no++) {
+    marker_present[seq_no] = 0;
+  }
+
+  for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) {
+    if (marker_is_icc(marker)) {
+      if (num_markers == 0) {
+        num_markers = GETJOCTET(marker->data[13]);
+      } else if (num_markers != GETJOCTET(marker->data[13])) {
+        return FALSE; /* inconsistent num_markers fields */
+      }
+      seq_no = GETJOCTET(marker->data[12]);
+      if (seq_no <= 0 || seq_no > num_markers) {
+        return FALSE; /* bogus sequence number */
+      }
+      if (marker_present[seq_no]) {
+        return FALSE; /* duplicate sequence numbers */
+      }
+      marker_present[seq_no] = 1;
+      data_length[seq_no] = marker->data_length - ICC_OVERHEAD_LEN;
+    }
+  }
+
+  if (num_markers == 0) {
+    return FALSE;
+  }
+
+  /* Check for missing markers, count total space needed,
+   * compute offset of each marker's part of the data.
+   */
+
+  total_length = 0;
+  for (seq_no = 1; seq_no <= num_markers; seq_no++) {
+    if (marker_present[seq_no] == 0) {
+      return FALSE; /* missing sequence number */
+    }
+    data_offset[seq_no] = total_length;
+    total_length += data_length[seq_no];
+  }
+
+  if (total_length <= 0) {
+    return FALSE; /* found only empty markers? */
+  }
+
+  /* Allocate space for assembled data */
+  icc_data = (JOCTET*)malloc(total_length * sizeof(JOCTET));
+  if (icc_data == NULL) {
+    return FALSE; /* oops, out of memory */
+  }
+
+  /* and fill it in */
+  for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) {
+    if (marker_is_icc(marker)) {
+      JOCTET FAR* src_ptr;
+      JOCTET* dst_ptr;
+      unsigned int length;
+      seq_no = GETJOCTET(marker->data[12]);
+      dst_ptr = icc_data + data_offset[seq_no];
+      src_ptr = marker->data + ICC_OVERHEAD_LEN;
+      length = data_length[seq_no];
+      while (length--) {
+        *dst_ptr++ = *src_ptr++;
+      }
+    }
+  }
+
+  *icc_data_ptr = icc_data;
+  *icc_data_len = total_length;
+
+  return TRUE;
+}
diff --git a/image/decoders/iccjpeg.h b/image/decoders/iccjpeg.h
new file mode 100644
index 0000000000..4d48144a23
--- /dev/null
+++ b/image/decoders/iccjpeg.h
@@ -0,0 +1,65 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * iccjpeg.h
+ *
+ * This file provides code to read and write International Color Consortium
+ * (ICC) device profiles embedded in JFIF JPEG image files.  The ICC has
+ * defined a standard format for including such data in JPEG "APP2" markers.
+ * The code given here does not know anything about the internal structure
+ * of the ICC profile data; it just knows how to put the profile data into
+ * a JPEG file being written, or get it back out when reading.
+ *
+ * This code depends on new features added to the IJG JPEG library as of
+ * IJG release 6b; it will not compile or work with older IJG versions.
+ *
+ * NOTE: this code would need surgery to work on 16-bit-int machines
+ * with ICC profiles exceeding 64K bytes in size.  See iccprofile.c
+ * for details.
+ */
+
+#ifndef mozilla_image_decoders_iccjpeg_h
+#define mozilla_image_decoders_iccjpeg_h
+
+#include <stdio.h> /* needed to define "FILE", "NULL" */
+#include "jpeglib.h"
+
+/*
+ * Reading a JPEG file that may contain an ICC profile requires two steps:
+ *
+ * 1. After jpeg_create_decompress() but before jpeg_read_header(),
+ *    call setup_read_icc_profile().  This routine tells the IJG library
+ *    to save in memory any APP2 markers it may find in the file.
+ *
+ * 2. After jpeg_read_header(), call read_icc_profile() to find out
+ *    whether there was a profile and obtain it if so.
+ */
+
+/*
+ * Prepare for reading an ICC profile
+ */
+
+extern void setup_read_icc_profile JPP((j_decompress_ptr cinfo));
+
+/*
+ * See if there was an ICC profile in the JPEG file being read;
+ * if so, reassemble and return the profile data.
+ *
+ * TRUE is returned if an ICC profile was found, FALSE if not.
+ * If TRUE is returned, *icc_data_ptr is set to point to the
+ * returned data, and *icc_data_len is set to its length.
+ *
+ * IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
+ * and must be freed by the caller with free() when the caller no longer
+ * needs it.  (Alternatively, we could write this routine to use the
+ * IJG library's memory allocator, so that the data would be freed implicitly
+ * at jpeg_finish_decompress() time.  But it seems likely that many apps
+ * will prefer to have the data stick around after decompression finishes.)
+ */
+
+extern boolean read_icc_profile JPP((j_decompress_ptr cinfo,
+                                     JOCTET** icc_data_ptr,
+                                     unsigned int* icc_data_len));
+#endif  // mozilla_image_decoders_iccjpeg_h
diff --git a/image/decoders/icon/android/moz.build b/image/decoders/icon/android/moz.build
new file mode 100644
index 0000000000..a99ae228d4
--- /dev/null
+++ b/image/decoders/icon/android/moz.build
@@ -0,0 +1,13 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+SOURCES += [
+    "nsIconChannel.cpp",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
diff --git a/image/decoders/icon/android/nsIconChannel.cpp b/image/decoders/icon/android/nsIconChannel.cpp
new file mode 100644
index 0000000000..7599cf2bb7
--- /dev/null
+++ b/image/decoders/icon/android/nsIconChannel.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdlib.h>
+#include "mozilla/gfx/Swizzle.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/NullPrincipal.h"
+#include "nsMimeTypes.h"
+#include "nsXULAppAPI.h"
+#include "AndroidBridge.h"
+#include "nsIconChannel.h"
+#include "nsIIconURI.h"
+#include "nsIStringStream.h"
+#include "nsNetUtil.h"
+#include "nsComponentManagerUtils.h"
+
+NS_IMPL_ISUPPORTS(nsIconChannel, nsIRequest, nsIChannel)
+
+using namespace mozilla;
+using mozilla::dom::ContentChild;
+
+static nsresult GetIconForExtension(const nsACString& aFileExt,
+                                    uint32_t aIconSize, uint8_t* const aBuf) {
+  if (!AndroidBridge::Bridge()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  AndroidBridge::Bridge()->GetIconForExtension(aFileExt, aIconSize, aBuf);
+
+  return NS_OK;
+}
+
+static nsresult CallRemoteGetIconForExtension(const nsACString& aFileExt,
+                                              uint32_t aIconSize,
+                                              uint8_t* const aBuf) {
+  NS_ENSURE_TRUE(aBuf != nullptr, NS_ERROR_NULL_POINTER);
+
+  // An array has to be used to get data from remote process
+  nsTArray<uint8_t> bits;
+  uint32_t bufSize = aIconSize * aIconSize * 4;
+
+  if (!ContentChild::GetSingleton()->SendGetIconForExtension(
+          PromiseFlatCString(aFileExt), aIconSize, &bits)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  NS_ASSERTION(bits.Length() == bufSize, "Pixels array is incomplete");
+  if (bits.Length() != bufSize) {
+    return NS_ERROR_FAILURE;
+  }
+
+  memcpy(aBuf, bits.Elements(), bufSize);
+
+  return NS_OK;
+}
+
+static nsresult moz_icon_to_channel(nsIURI* aURI, const nsACString& aFileExt,
+                                    uint32_t aIconSize, nsIChannel** aChannel) {
+  NS_ENSURE_TRUE(aIconSize < 256 && aIconSize > 0, NS_ERROR_UNEXPECTED);
+
+  int width = aIconSize;
+  int height = aIconSize;
+
+  // moz-icon data should have two bytes for the size,
+  // then the ARGB pixel values with pre-multiplied Alpha
+  const int channels = 4;
+  CheckedInt32 buf_size =
+      4 + channels * CheckedInt32(height) * CheckedInt32(width);
+  if (!buf_size.isValid()) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  uint8_t* const buf = (uint8_t*)moz_xmalloc(buf_size.value());
+  uint8_t* out = buf;
+
+  *(out++) = width;
+  *(out++) = height;
+  *(out++) = uint8_t(mozilla::gfx::SurfaceFormat::R8G8B8A8);
+
+  // Set all bits to ensure in nsIconDecoder we color manage and premultiply.
+  *(out++) = 0xFF;
+
+  nsresult rv;
+  if (XRE_IsParentProcess()) {
+    rv = GetIconForExtension(aFileExt, aIconSize, out);
+  } else {
+    rv = CallRemoteGetIconForExtension(aFileExt, aIconSize, out);
+  }
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIStringInputStream> stream =
+      do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = stream->AdoptData((char*)buf, buf_size.value());
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // nsIconProtocolHandler::NewChannel will provide the correct loadInfo for
+  // this iconChannel. Use the most restrictive security settings for the
+  // temporary loadInfo to make sure the channel can not be opened.
+  nsCOMPtr<nsIPrincipal> nullPrincipal =
+      NullPrincipal::CreateWithoutOriginAttributes();
+  return NS_NewInputStreamChannel(
+      aChannel, aURI, stream.forget(), nullPrincipal,
+      nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
+      nsIContentPolicy::TYPE_INTERNAL_IMAGE, nsLiteralCString(IMAGE_ICON_MS));
+}
+
+nsresult nsIconChannel::Init(nsIURI* aURI) {
+  nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
+  NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");
+
+  nsAutoCString stockIcon;
+  iconURI->GetStockIcon(stockIcon);
+
+  uint32_t desiredImageSize;
+  iconURI->GetImageSize(&desiredImageSize);
+
+  nsAutoCString iconFileExt;
+  iconURI->GetFileExtension(iconFileExt);
+
+  return moz_icon_to_channel(iconURI, iconFileExt, desiredImageSize,
+                             getter_AddRefs(mRealChannel));
+}
diff --git a/image/decoders/icon/android/nsIconChannel.h b/image/decoders/icon/android/nsIconChannel.h
new file mode 100644
index 0000000000..e25196c6ee
--- /dev/null
+++ b/image/decoders/icon/android/nsIconChannel.h
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_icon_android_nsIconChannel_h
+#define mozilla_image_decoders_icon_android_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsIChannel.h"
+#include "nsIURI.h"
+#include "nsCOMPtr.h"
+
+/**
+ * This class is the Android implementation of nsIconChannel.
+ * It asks Android for an icon, and creates a new channel for
+ * that file to which all calls will be proxied.
+ */
+class nsIconChannel final : public nsIChannel {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_FORWARD_NSIREQUEST(mRealChannel->)
+  NS_FORWARD_NSICHANNEL(mRealChannel->)
+
+  nsIconChannel() {}
+
+  /**
+   * Called by nsIconProtocolHandler after it creates this channel.
+   * Must be called before calling any other function on this object.
+   * If this method fails, no other function must be called on this object.
+   */
+  nsresult Init(nsIURI* aURI);
+
+ private:
+  ~nsIconChannel() {}
+
+  /**
+   * The channel to the temp icon file (e.g. to /tmp/2qy9wjqw.html).
+   * Will always be non-null after a successful Init.
+   */
+  nsCOMPtr<nsIChannel> mRealChannel;
+};
+
+#endif  // mozilla_image_decoders_icon_android_nsIconChannel_h
diff --git a/image/decoders/icon/components.conf b/image/decoders/icon/components.conf
new file mode 100644
index 0000000000..68bff8e231
--- /dev/null
+++ b/image/decoders/icon/components.conf
@@ -0,0 +1,29 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = [
+    {
+        'cid': '{d0f9db12-249c-11d5-9905-001083010e9b}',
+        'contract_ids': ['@mozilla.org/network/protocol;1?name=moz-icon'],
+        'type': 'nsIconProtocolHandler',
+        'headers': ['/image/decoders/icon/nsIconProtocolHandler.h'],
+        'protocol_config': {
+            'scheme': 'moz-icon',
+            'flags': [
+                'URI_NORELATIVE',
+                'URI_NOAUTH',
+                'URI_IS_UI_RESOURCE',
+                'URI_IS_LOCAL_RESOURCE',
+            ],
+            'default_port': 0,
+        },
+    },
+    {
+        'cid': '{1460df3b-774c-4205-8349-838e507c3ef9}',
+        'type': 'nsMozIconURI::Mutator',
+        'headers': ['/image/decoders/icon/nsIconURI.h'],
+    },
+]
diff --git a/image/decoders/icon/gtk/moz.build b/image/decoders/icon/gtk/moz.build
new file mode 100644
index 0000000000..3eac86b6ba
--- /dev/null
+++ b/image/decoders/icon/gtk/moz.build
@@ -0,0 +1,20 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+SOURCES += [
+    "nsIconChannel.cpp",
+]
+
+EXPORTS += [
+    "nsIconChannel.h",
+]
+
+FINAL_LIBRARY = "xul"
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
+    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+
+include("/ipc/chromium/chromium-config.mozbuild")
diff --git a/image/decoders/icon/gtk/nsIconChannel.cpp b/image/decoders/icon/gtk/nsIconChannel.cpp
new file mode 100644
index 0000000000..e45c63665f
--- /dev/null
+++ b/image/decoders/icon/gtk/nsIconChannel.cpp
@@ -0,0 +1,480 @@
+/* vim:set ts=2 sw=2 sts=2 cin et: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIconChannel.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/NullPrincipal.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/gfx/Swizzle.h"
+#include "mozilla/ipc/ByteBuf.h"
+#include <algorithm>
+
+#include <gio/gio.h>
+
+#include <gtk/gtk.h>
+
+#include "nsMimeTypes.h"
+#include "nsIMIMEService.h"
+
+#include "nsServiceManagerUtils.h"
+
+#include "nsNetUtil.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIStringStream.h"
+#include "nsServiceManagerUtils.h"
+#include "nsIURL.h"
+#include "nsIPipe.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "prlink.h"
+#include "gfxPlatform.h"
+
+using mozilla::CheckedInt32;
+using mozilla::ipc::ByteBuf;
+
+NS_IMPL_ISUPPORTS(nsIconChannel, nsIRequest, nsIChannel)
+
+static nsresult MozGdkPixbufToByteBuf(GdkPixbuf* aPixbuf, ByteBuf* aByteBuf) {
+  int width = gdk_pixbuf_get_width(aPixbuf);
+  int height = gdk_pixbuf_get_height(aPixbuf);
+  NS_ENSURE_TRUE(height < 256 && width < 256 && height > 0 && width > 0 &&
+                     gdk_pixbuf_get_colorspace(aPixbuf) == GDK_COLORSPACE_RGB &&
+                     gdk_pixbuf_get_bits_per_sample(aPixbuf) == 8 &&
+                     gdk_pixbuf_get_has_alpha(aPixbuf) &&
+                     gdk_pixbuf_get_n_channels(aPixbuf) == 4,
+                 NS_ERROR_UNEXPECTED);
+
+  const int n_channels = 4;
+  CheckedInt32 buf_size =
+      4 + n_channels * CheckedInt32(height) * CheckedInt32(width);
+  if (!buf_size.isValid()) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  uint8_t* const buf = (uint8_t*)moz_xmalloc(buf_size.value());
+  uint8_t* out = buf;
+
+  *(out++) = width;
+  *(out++) = height;
+  *(out++) = uint8_t(mozilla::gfx::SurfaceFormat::OS_RGBA);
+
+  // Set all bits to ensure in nsIconDecoder we color manage and premultiply.
+  *(out++) = 0xFF;
+
+  const guchar* const pixels = gdk_pixbuf_get_pixels(aPixbuf);
+  int instride = gdk_pixbuf_get_rowstride(aPixbuf);
+  int outstride = width * n_channels;
+
+  // encode the RGB data and the A data and adjust the stride as necessary.
+  mozilla::gfx::SwizzleData(pixels, instride,
+                            mozilla::gfx::SurfaceFormat::R8G8B8A8, out,
+                            outstride, mozilla::gfx::SurfaceFormat::OS_RGBA,
+                            mozilla::gfx::IntSize(width, height));
+
+  *aByteBuf = ByteBuf(buf, buf_size.value(), buf_size.value());
+  return NS_OK;
+}
+
+static nsresult ByteBufToStream(ByteBuf&& aBuf, nsIInputStream** aStream) {
+  nsresult rv;
+  nsCOMPtr<nsIStringInputStream> stream =
+      do_CreateInstance("@mozilla.org/io/string-input-stream;1", &rv);
+
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  // stream takes ownership of buf and will free it on destruction.
+  // This function cannot fail.
+  rv = stream->AdoptData(reinterpret_cast<char*>(aBuf.mData), aBuf.mLen);
+  MOZ_ASSERT(CheckedInt32(aBuf.mLen).isValid(),
+             "aBuf.mLen should fit in int32_t");
+  aBuf.mData = nullptr;
+
+  // If this no longer holds then re-examine buf's lifetime.
+  MOZ_ASSERT(NS_SUCCEEDED(rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  stream.forget(aStream);
+  return NS_OK;
+}
+
+static nsresult StreamToChannel(already_AddRefed<nsIInputStream> aStream,
+                                nsIURI* aURI, nsIChannel** aChannel) {
+  // nsIconProtocolHandler::NewChannel will provide the correct loadInfo for
+  // this iconChannel. Use the most restrictive security settings for the
+  // temporary loadInfo to make sure the channel can not be opened.
+  nsCOMPtr<nsIPrincipal> nullPrincipal =
+      mozilla::NullPrincipal::CreateWithoutOriginAttributes();
+  return NS_NewInputStreamChannel(
+      aChannel, aURI, std::move(aStream), nullPrincipal,
+      nsILoadInfo::SEC_REQUIRE_SAME_ORIGIN_DATA_IS_BLOCKED,
+      nsIContentPolicy::TYPE_INTERNAL_IMAGE, nsLiteralCString(IMAGE_ICON_MS));
+}
+
+static GtkWidget* gProtoWindow = nullptr;
+static GtkWidget* gStockImageWidget = nullptr;
+
+static void ensure_stock_image_widget() {
+  // Only the style of the GtkImage needs to be used, but the widget is kept
+  // to track dynamic style changes.
+  if (!gProtoWindow) {
+    gProtoWindow = gtk_window_new(GTK_WINDOW_POPUP);
+    GtkWidget* protoLayout = gtk_fixed_new();
+    gtk_container_add(GTK_CONTAINER(gProtoWindow), protoLayout);
+
+    gStockImageWidget = gtk_image_new();
+    gtk_container_add(GTK_CONTAINER(protoLayout), gStockImageWidget);
+
+    gtk_widget_ensure_style(gStockImageWidget);
+  }
+}
+
+static GtkIconSize moz_gtk_icon_size(const char* name) {
+  if (strcmp(name, "button") == 0) {
+    return GTK_ICON_SIZE_BUTTON;
+  }
+
+  if (strcmp(name, "menu") == 0) {
+    return GTK_ICON_SIZE_MENU;
+  }
+
+  if (strcmp(name, "toolbar") == 0) {
+    return GTK_ICON_SIZE_LARGE_TOOLBAR;
+  }
+
+  if (strcmp(name, "toolbarsmall") == 0) {
+    return GTK_ICON_SIZE_SMALL_TOOLBAR;
+  }
+
+  if (strcmp(name, "dnd") == 0) {
+    return GTK_ICON_SIZE_DND;
+  }
+
+  if (strcmp(name, "dialog") == 0) {
+    return GTK_ICON_SIZE_DIALOG;
+  }
+
+  return GTK_ICON_SIZE_MENU;
+}
+
+static int32_t GetIconSize(nsIMozIconURI* aIconURI) {
+  nsAutoCString iconSizeString;
+
+  aIconURI->GetIconSize(iconSizeString);
+  if (iconSizeString.IsEmpty()) {
+    uint32_t size;
+    mozilla::DebugOnly<nsresult> rv = aIconURI->GetImageSize(&size);
+    NS_ASSERTION(NS_SUCCEEDED(rv), "GetImageSize failed");
+    return size;
+  }
+  int size;
+
+  GtkIconSize icon_size = moz_gtk_icon_size(iconSizeString.get());
+  gtk_icon_size_lookup(icon_size, &size, nullptr);
+  return size;
+}
+
+/* Scale icon buffer to preferred size */
+static nsresult ScaleIconBuf(GdkPixbuf** aBuf, int32_t iconSize) {
+  // Scale buffer only if width or height differ from preferred size
+  if (gdk_pixbuf_get_width(*aBuf) != iconSize &&
+      gdk_pixbuf_get_height(*aBuf) != iconSize) {
+    GdkPixbuf* scaled =
+        gdk_pixbuf_scale_simple(*aBuf, iconSize, iconSize, GDK_INTERP_BILINEAR);
+    // replace original buffer by scaled
+    g_object_unref(*aBuf);
+    *aBuf = scaled;
+    if (!scaled) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+  }
+  return NS_OK;
+}
+
+/* static */
+nsresult nsIconChannel::GetIconWithGIO(nsIMozIconURI* aIconURI,
+                                       ByteBuf* aDataOut) {
+  GIcon* icon = nullptr;
+  nsCOMPtr<nsIURL> fileURI;
+
+  // Read icon content
+  aIconURI->GetIconURL(getter_AddRefs(fileURI));
+
+  // Get icon for file specified by URI
+  if (fileURI) {
+    nsAutoCString spec;
+    fileURI->GetAsciiSpec(spec);
+    if (fileURI->SchemeIs("file")) {
+      GFile* file = g_file_new_for_uri(spec.get());
+      GFileInfo* fileInfo =
+          g_file_query_info(file, G_FILE_ATTRIBUTE_STANDARD_ICON,
+                            G_FILE_QUERY_INFO_NONE, nullptr, nullptr);
+      g_object_unref(file);
+      if (fileInfo) {
+        // icon from g_content_type_get_icon doesn't need unref
+        icon = g_file_info_get_icon(fileInfo);
+        if (icon) {
+          g_object_ref(icon);
+        }
+        g_object_unref(fileInfo);
+      }
+    }
+  }
+
+  // Try to get icon by using MIME type
+  if (!icon) {
+    nsAutoCString type;
+    aIconURI->GetContentType(type);
+    // Try to get MIME type from file extension by using nsIMIMEService
+    if (type.IsEmpty()) {
+      nsCOMPtr<nsIMIMEService> ms(do_GetService("@mozilla.org/mime;1"));
+      if (ms) {
+        nsAutoCString fileExt;
+        aIconURI->GetFileExtension(fileExt);
+        ms->GetTypeFromExtension(fileExt, type);
+      }
+    }
+    char* ctype = nullptr;  // character representation of content type
+    if (!type.IsEmpty()) {
+      ctype = g_content_type_from_mime_type(type.get());
+    }
+    if (ctype) {
+      icon = g_content_type_get_icon(ctype);
+      g_free(ctype);
+    }
+  }
+
+  // Get default icon theme
+  GtkIconTheme* iconTheme = gtk_icon_theme_get_default();
+  GtkIconInfo* iconInfo = nullptr;
+  // Get icon size
+  int32_t iconSize = GetIconSize(aIconURI);
+
+  if (icon) {
+    // Use icon and theme to get GtkIconInfo
+    iconInfo = gtk_icon_theme_lookup_by_gicon(iconTheme, icon, iconSize,
+                                              (GtkIconLookupFlags)0);
+    g_object_unref(icon);
+  }
+
+  if (!iconInfo) {
+    // Mozilla's mimetype lookup failed. Try the "unknown" icon.
+    iconInfo = gtk_icon_theme_lookup_icon(iconTheme, "unknown", iconSize,
+                                          (GtkIconLookupFlags)0);
+    if (!iconInfo) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  // Create a GdkPixbuf buffer containing icon and scale it
+  GdkPixbuf* buf = gtk_icon_info_load_icon(iconInfo, nullptr);
+  gtk_icon_info_free(iconInfo);
+  if (!buf) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  nsresult rv = ScaleIconBuf(&buf, iconSize);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = MozGdkPixbufToByteBuf(buf, aDataOut);
+  g_object_unref(buf);
+  return rv;
+}
+
+/* static */
+nsresult nsIconChannel::GetIcon(nsIURI* aURI, ByteBuf* aDataOut) {
+  nsCOMPtr<nsIMozIconURI> iconURI = do_QueryInterface(aURI);
+  NS_ASSERTION(iconURI, "URI is not an nsIMozIconURI");
+
+  if (gfxPlatform::IsHeadless()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsAutoCString stockIcon;
+  iconURI->GetStockIcon(stockIcon);
+  if (stockIcon.IsEmpty()) {
+    return GetIconWithGIO(iconURI, aDataOut);
+  }
+
+  // Search for stockIcon
+  nsAutoCString iconSizeString;
+  iconURI->GetIconSize(iconSizeString);
+
+  nsAutoCString iconStateString;
+  iconURI->GetIconState(iconStateString);
+
+  GtkIconSize icon_size = moz_gtk_icon_size(iconSizeString.get());
+  GtkStateType state = iconStateString.EqualsLiteral("disabled")
+                           ? GTK_STATE_INSENSITIVE
+                           : GTK_STATE_NORMAL;
+
+  // First lookup the icon by stock id and text direction.
+  GtkTextDirection direction = GTK_TEXT_DIR_NONE;
+  if (StringEndsWith(stockIcon, "-ltr"_ns)) {
+    direction = GTK_TEXT_DIR_LTR;
+  } else if (StringEndsWith(stockIcon, "-rtl"_ns)) {
+    direction = GTK_TEXT_DIR_RTL;
+  }
+
+  bool forceDirection = direction != GTK_TEXT_DIR_NONE;
+  nsAutoCString stockID;
+  bool useIconName = false;
+  if (!forceDirection) {
+    direction = gtk_widget_get_default_direction();
+    stockID = stockIcon;
+  } else {
+    // GTK versions < 2.22 use icon names from concatenating stock id with
+    // -(rtl|ltr), which is how the moz-icon stock name is interpreted here.
+    stockID = Substring(stockIcon, 0, stockIcon.Length() - 4);
+    // However, if we lookup bidi icons by the stock name, then GTK versions
+    // >= 2.22 will use a bidi lookup convention that most icon themes do not
+    // yet follow.  Therefore, we first check to see if the theme supports the
+    // old icon name as this will have bidi support (if found).
+    GtkIconTheme* icon_theme = gtk_icon_theme_get_default();
+    // Micking what gtk_icon_set_render_icon does with sizes, though it's not
+    // critical as icons will be scaled to suit size.  It just means we follow
+    // the same paths and so share caches.
+    gint width, height;
+    if (gtk_icon_size_lookup(icon_size, &width, &height)) {
+      gint size = std::min(width, height);
+      // We use gtk_icon_theme_lookup_icon() without
+      // GTK_ICON_LOOKUP_USE_BUILTIN instead of gtk_icon_theme_has_icon() so
+      // we don't pick up fallback icons added by distributions for backward
+      // compatibility.
+      GtkIconInfo* icon = gtk_icon_theme_lookup_icon(
+          icon_theme, stockIcon.get(), size, (GtkIconLookupFlags)0);
+      if (icon) {
+        useIconName = true;
+        gtk_icon_info_free(icon);
+      }
+    }
+  }
+
+  ensure_stock_image_widget();
+  GtkStyle* style = gtk_widget_get_style(gStockImageWidget);
+  GtkIconSet* icon_set = nullptr;
+  if (!useIconName) {
+    icon_set = gtk_style_lookup_icon_set(style, stockID.get());
+  }
+
+  if (!icon_set) {
+    // Either we have chosen icon-name lookup for a bidi icon, or stockIcon is
+    // not a stock id so we assume it is an icon name.
+    useIconName = true;
+    // Creating a GtkIconSet is a convenient way to allow the style to
+    // render the icon, possibly with variations suitable for insensitive
+    // states.
+    icon_set = gtk_icon_set_new();
+    GtkIconSource* icon_source = gtk_icon_source_new();
+
+    gtk_icon_source_set_icon_name(icon_source, stockIcon.get());
+    gtk_icon_set_add_source(icon_set, icon_source);
+    gtk_icon_source_free(icon_source);
+  }
+
+  GdkPixbuf* icon = gtk_icon_set_render_icon(
+      icon_set, style, direction, state, icon_size, gStockImageWidget, nullptr);
+  if (useIconName) {
+    gtk_icon_set_unref(icon_set);
+  }
+
+  // According to documentation, gtk_icon_set_render_icon() never returns
+  // nullptr, but it does return nullptr when we have the problem reported
+  // here: https://bugzilla.gnome.org/show_bug.cgi?id=629878#c13
+  if (!icon) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  nsresult rv = MozGdkPixbufToByteBuf(icon, aDataOut);
+
+  g_object_unref(icon);
+
+  return rv;
+}
+
+nsresult nsIconChannel::Init(nsIURI* aURI) {
+  nsCOMPtr<nsIInputStream> stream;
+
+  using ContentChild = mozilla::dom::ContentChild;
+  if (auto* contentChild = ContentChild::GetSingleton()) {
+    // Get the icon via IPC and translate the promise of a ByteBuf
+    // into an actually-existing channel.
+    RefPtr<ContentChild::GetSystemIconPromise> icon =
+        contentChild->SendGetSystemIcon(aURI);
+    if (!icon) {
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    nsCOMPtr<nsIAsyncInputStream> inputStream;
+    nsCOMPtr<nsIAsyncOutputStream> outputStream;
+    NS_NewPipe2(getter_AddRefs(inputStream), getter_AddRefs(outputStream), true,
+                false, 0, UINT32_MAX);
+
+    // FIXME: Bug 1718324
+    // The GetSystemIcon() call will end up on the parent doing GetIcon()
+    // and by using ByteBuf we might not be immune to some deadlock, at least
+    // on paper. From analysis in
+    // https://phabricator.services.mozilla.com/D118596#3865440 we should be
+    // safe in practice, but it would be nicer to just write that differently.
+
+    icon->Then(
+        mozilla::GetCurrentSerialEventTarget(), __func__,
+        [outputStream](
+            mozilla::Tuple<nsresult, mozilla::Maybe<ByteBuf>>&& aArg) {
+          nsresult rv = mozilla::Get<0>(aArg);
+          mozilla::Maybe<ByteBuf> bytes = std::move(mozilla::Get<1>(aArg));
+
+          if (NS_SUCCEEDED(rv)) {
+            MOZ_RELEASE_ASSERT(bytes);
+            uint32_t written;
+            rv = outputStream->Write(reinterpret_cast<char*>(bytes->mData),
+                                     static_cast<uint32_t>(bytes->mLen),
+                                     &written);
+            if (NS_SUCCEEDED(rv)) {
+              const bool wroteAll = static_cast<size_t>(written) == bytes->mLen;
+              MOZ_ASSERT(wroteAll);
+              if (!wroteAll) {
+                rv = NS_ERROR_UNEXPECTED;
+              }
+            }
+          } else {
+            MOZ_ASSERT(!bytes);
+          }
+
+          if (NS_FAILED(rv)) {
+            outputStream->CloseWithStatus(rv);
+          }
+        },
+        [outputStream](mozilla::ipc::ResponseRejectReason) {
+          outputStream->CloseWithStatus(NS_ERROR_FAILURE);
+        });
+
+    stream = inputStream.forget();
+  } else {
+    // Get the icon directly.
+    ByteBuf bytebuf;
+    nsresult rv = GetIcon(aURI, &bytebuf);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = ByteBufToStream(std::move(bytebuf), getter_AddRefs(stream));
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return StreamToChannel(stream.forget(), aURI, getter_AddRefs(mRealChannel));
+}
+
+void nsIconChannel::Shutdown() {
+  if (gProtoWindow) {
+    gtk_widget_destroy(gProtoWindow);
+    gProtoWindow = nullptr;
+    gStockImageWidget = nullptr;
+  }
+}
diff --git a/image/decoders/icon/gtk/nsIconChannel.h b/image/decoders/icon/gtk/nsIconChannel.h
new file mode 100644
index 0000000000..6ad26602d0
--- /dev/null
+++ b/image/decoders/icon/gtk/nsIconChannel.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_icon_gtk_nsIconChannel_h
+#define mozilla_image_decoders_icon_gtk_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsIChannel.h"
+#include "nsIURI.h"
+#include "nsIIconURI.h"
+#include "nsCOMPtr.h"
+
+namespace mozilla::ipc {
+class ByteBuf;
+}
+
+/// This class is the GTK implementation of nsIconChannel.  It asks
+/// GTK for the icon, translates the pixel data in-memory into
+/// nsIconDecoder format, and proxies the nsChannel interface to a new
+/// channel returning that image.
+class nsIconChannel final : public nsIChannel {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_FORWARD_NSIREQUEST(mRealChannel->)
+  NS_FORWARD_NSICHANNEL(mRealChannel->)
+
+  nsIconChannel() {}
+
+  static void Shutdown();
+
+  /// Called by nsIconProtocolHandler after it creates this channel.
+  /// Must be called before calling any other function on this object.
+  /// If this method fails, no other function must be called on this object.
+  nsresult Init(nsIURI* aURI);
+
+  /// Obtains an icon, in nsIconDecoder format, as a ByteBuf instead
+  /// of a channel.  For use with IPC.
+  static nsresult GetIcon(nsIURI* aURI, mozilla::ipc::ByteBuf* aDataOut);
+
+ private:
+  ~nsIconChannel() {}
+  /// The input stream channel which will yield the image.
+  /// Will always be non-null after a successful Init.
+  nsCOMPtr<nsIChannel> mRealChannel;
+
+  static nsresult GetIconWithGIO(nsIMozIconURI* aIconURI,
+                                 mozilla::ipc::ByteBuf* aDataOut);
+};
+
+#endif  // mozilla_image_decoders_icon_gtk_nsIconChannel_h
diff --git a/image/decoders/icon/mac/moz.build b/image/decoders/icon/mac/moz.build
new file mode 100644
index 0000000000..3467659a8f
--- /dev/null
+++ b/image/decoders/icon/mac/moz.build
@@ -0,0 +1,13 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+SOURCES += [
+    "nsIconChannelCocoa.mm",
+]
+
+FINAL_LIBRARY = "xul"
+
+include("/ipc/chromium/chromium-config.mozbuild")
diff --git a/image/decoders/icon/mac/nsIconChannel.h b/image/decoders/icon/mac/nsIconChannel.h
new file mode 100644
index 0000000000..dca2a3c51a
--- /dev/null
+++ b/image/decoders/icon/mac/nsIconChannel.h
@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_encoders_icon_mac_nsIconChannel_h
+#define mozilla_image_encoders_icon_mac_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsIChannel.h"
+#include "nsILoadGroup.h"
+#include "nsILoadInfo.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIInputStreamPump.h"
+#include "nsIStreamListener.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+
+class nsIFile;
+
+class nsIconChannel final : public nsIChannel, public nsIStreamListener {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSICHANNEL
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  nsIconChannel();
+
+  nsresult Init(nsIURI* uri);
+
+ protected:
+  virtual ~nsIconChannel();
+
+  nsCOMPtr<nsIURI> mUrl;
+  nsCOMPtr<nsIURI> mOriginalURI;
+  nsCOMPtr<nsILoadGroup> mLoadGroup;
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsISupports> mOwner;
+  nsCOMPtr<nsILoadInfo> mLoadInfo;
+
+  nsCOMPtr<nsIInputStreamPump> mPump;
+  nsCOMPtr<nsIStreamListener> mListener;
+  bool mCanceled = false;
+
+  [[nodiscard]] nsresult MakeInputStream(nsIInputStream** _retval,
+                                         bool nonBlocking);
+
+  nsresult ExtractIconInfoFromUrl(nsIFile** aLocalFile,
+                                  uint32_t* aDesiredImageSize,
+                                  nsACString& aContentType,
+                                  nsACString& aFileExtension);
+};
+
+#endif  // mozilla_image_encoders_icon_mac_nsIconChannel_h
diff --git a/image/decoders/icon/mac/nsIconChannelCocoa.mm b/image/decoders/icon/mac/nsIconChannelCocoa.mm
new file mode 100644
index 0000000000..a6f0bebb3d
--- /dev/null
+++ b/image/decoders/icon/mac/nsIconChannelCocoa.mm
@@ -0,0 +1,500 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsContentUtils.h"
+#include "nsIconChannel.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/EndianUtils.h"
+#include "nsComponentManagerUtils.h"
+#include "nsIIconURI.h"
+#include "nsIInputStream.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsString.h"
+#include "nsMimeTypes.h"
+#include "nsIURL.h"
+#include "nsNetCID.h"
+#include "nsIPipe.h"
+#include "nsIOutputStream.h"
+#include "nsCExternalHandlerService.h"
+#include "nsILocalFileMac.h"
+#include "nsIFileURL.h"
+#include "nsTArray.h"
+#include "nsObjCExceptions.h"
+#include "nsProxyRelease.h"
+#include "nsContentSecurityManager.h"
+#include "nsNetUtil.h"
+#include "mozilla/RefPtr.h"
+
+#include <Cocoa/Cocoa.h>
+
+using namespace mozilla;
+
+// nsIconChannel methods
+nsIconChannel::nsIconChannel() {}
+
+nsIconChannel::~nsIconChannel() {
+  if (mLoadInfo) {
+    NS_ReleaseOnMainThread("nsIconChannel::mLoadInfo", mLoadInfo.forget());
+  }
+}
+
+NS_IMPL_ISUPPORTS(nsIconChannel, nsIChannel, nsIRequest, nsIRequestObserver, nsIStreamListener)
+
+nsresult nsIconChannel::Init(nsIURI* uri) {
+  NS_ASSERTION(uri, "no uri");
+  mUrl = uri;
+  mOriginalURI = uri;
+  nsresult rv;
+  mPump = do_CreateInstance(NS_INPUTSTREAMPUMP_CONTRACTID, &rv);
+  return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIRequest methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetName(nsACString& result) { return mUrl->GetSpec(result); }
+
+NS_IMETHODIMP
+nsIconChannel::IsPending(bool* result) { return mPump->IsPending(result); }
+
+NS_IMETHODIMP
+nsIconChannel::GetStatus(nsresult* status) { return mPump->GetStatus(status); }
+
+NS_IMETHODIMP nsIconChannel::SetCanceledReason(const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsIconChannel::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsIconChannel::CancelWithReason(nsresult aStatus, const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Cancel(nsresult status) {
+  mCanceled = true;
+  return mPump->Cancel(status);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetCanceled(bool* result) {
+  *result = mCanceled;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::Suspend(void) { return mPump->Suspend(); }
+
+NS_IMETHODIMP
+nsIconChannel::Resume(void) { return mPump->Resume(); }
+
+// nsIRequestObserver methods
+NS_IMETHODIMP
+nsIconChannel::OnStartRequest(nsIRequest* aRequest) {
+  if (mListener) {
+    return mListener->OnStartRequest(this);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+  if (mListener) {
+    mListener->OnStopRequest(this, aStatus);
+    mListener = nullptr;
+  }
+
+  // Remove from load group
+  if (mLoadGroup) {
+    mLoadGroup->RemoveRequest(this, nullptr, aStatus);
+  }
+
+  return NS_OK;
+}
+
+// nsIStreamListener methods
+NS_IMETHODIMP
+nsIconChannel::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aStream, uint64_t aOffset,
+                               uint32_t aCount) {
+  if (mListener) {
+    return mListener->OnDataAvailable(this, aStream, aOffset, aCount);
+  }
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIChannel methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetOriginalURI(nsIURI** aURI) {
+  *aURI = mOriginalURI;
+  NS_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOriginalURI(nsIURI* aURI) {
+  NS_ENSURE_ARG_POINTER(aURI);
+  mOriginalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetURI(nsIURI** aURI) {
+  *aURI = mUrl;
+  NS_IF_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::Open(nsIInputStream** _retval) {
+  nsCOMPtr<nsIStreamListener> listener;
+  nsresult rv = nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return MakeInputStream(_retval, false);
+}
+
+nsresult nsIconChannel::ExtractIconInfoFromUrl(nsIFile** aLocalFile, uint32_t* aDesiredImageSize,
+                                               nsACString& aContentType,
+                                               nsACString& aFileExtension) {
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMozIconURI> iconURI(do_QueryInterface(mUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  iconURI->GetImageSize(aDesiredImageSize);
+  iconURI->GetContentType(aContentType);
+  iconURI->GetFileExtension(aFileExtension);
+
+  nsCOMPtr<nsIURL> url;
+  rv = iconURI->GetIconURL(getter_AddRefs(url));
+  if (NS_FAILED(rv) || !url) return NS_OK;
+
+  nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(url, &rv);
+  if (NS_FAILED(rv) || !fileURL) return NS_OK;
+
+  nsCOMPtr<nsIFile> file;
+  rv = fileURL->GetFile(getter_AddRefs(file));
+  if (NS_FAILED(rv) || !file) return NS_OK;
+
+  nsCOMPtr<nsILocalFileMac> localFileMac(do_QueryInterface(file, &rv));
+  if (NS_FAILED(rv) || !localFileMac) return NS_OK;
+
+  *aLocalFile = file;
+  NS_IF_ADDREF(*aLocalFile);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::AsyncOpen(nsIStreamListener* aListener) {
+  nsCOMPtr<nsIStreamListener> listener = aListener;
+  nsresult rv = nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  if (NS_FAILED(rv)) {
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  MOZ_ASSERT(mLoadInfo->GetSecurityMode() == 0 || mLoadInfo->GetInitialSecurityCheckDone() ||
+                 (mLoadInfo->GetSecurityMode() ==
+                      nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL &&
+                  mLoadInfo->GetLoadingPrincipal() &&
+                  mLoadInfo->GetLoadingPrincipal()->IsSystemPrincipal()),
+             "security flags in loadInfo but doContentSecurityCheck() not called");
+
+  nsCOMPtr<nsIInputStream> inStream;
+  rv = MakeInputStream(getter_AddRefs(inStream), true);
+  if (NS_FAILED(rv)) {
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  // Init our stream pump
+  nsCOMPtr<nsIEventTarget> target =
+      nsContentUtils::GetEventTargetByLoadInfo(mLoadInfo, mozilla::TaskCategory::Other);
+  rv = mPump->Init(inStream, 0, 0, false, target);
+  if (NS_FAILED(rv)) {
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  rv = mPump->AsyncRead(this);
+  if (NS_SUCCEEDED(rv)) {
+    // Store our real listener
+    mListener = aListener;
+    // Add ourself to the load group, if available
+    if (mLoadGroup) {
+      mLoadGroup->AddRequest(this, nullptr);
+    }
+  } else {
+    mCallbacks = nullptr;
+  }
+
+  return rv;
+}
+
+nsresult nsIconChannel::MakeInputStream(nsIInputStream** _retval, bool aNonBlocking) {
+  NS_OBJC_BEGIN_TRY_BLOCK_RETURN;
+
+  nsCString contentType;
+  nsAutoCString fileExt;
+  nsCOMPtr<nsIFile> fileloc;  // file we want an icon for
+  uint32_t desiredImageSize;
+  nsresult rv =
+      ExtractIconInfoFromUrl(getter_AddRefs(fileloc), &desiredImageSize, contentType, fileExt);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  bool fileExists = false;
+  if (fileloc) {
+    fileloc->Exists(&fileExists);
+  }
+
+  NSImage* iconImage = nil;
+
+  // first try to get the icon from the file if it exists
+  if (fileExists) {
+    nsCOMPtr<nsILocalFileMac> localFileMac(do_QueryInterface(fileloc, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    CFURLRef macURL;
+    if (NS_SUCCEEDED(localFileMac->GetCFURL(&macURL))) {
+      iconImage = [[NSWorkspace sharedWorkspace] iconForFile:[(NSURL*)macURL path]];
+      ::CFRelease(macURL);
+    }
+  }
+
+  // if we don't have an icon yet try to get one by extension
+  if (!iconImage && !fileExt.IsEmpty()) {
+    NSString* fileExtension = [NSString stringWithUTF8String:fileExt.get()];
+    iconImage = [[NSWorkspace sharedWorkspace] iconForFileType:fileExtension];
+  }
+
+  // If we still don't have an icon, get the generic document icon.
+  if (!iconImage) {
+    iconImage = [[NSWorkspace sharedWorkspace] iconForFileType:NSFileTypeUnknown];
+  }
+
+  if (!iconImage) {
+    return NS_ERROR_FAILURE;
+  }
+
+  if (desiredImageSize > 255) {
+    // The Icon image format represents width and height as u8, so it does not
+    // allow for images sized 256 or more.
+    return NS_ERROR_FAILURE;
+  }
+
+  // Set the actual size to *twice* the requested size.
+  // We do this because our UI doesn't take the window's device pixel ratio into
+  // account when it requests these icons; e.g. it will request an icon with
+  // size 16, place it in a 16x16 CSS pixel sized image, and then display it in
+  // a window on a HiDPI screen where the icon now covers 32x32 physical screen
+  // pixels. So we just always double the size here in order to prevent blurriness.
+  uint32_t size = (desiredImageSize < 128) ? desiredImageSize * 2 : desiredImageSize;
+  uint32_t width = size;
+  uint32_t height = size;
+
+  // The "image format" we're outputting here (and which gets decoded by
+  // nsIconDecoder) has the following format:
+  //  - 1 byte for the image width, as u8
+  //  - 1 byte for the image height, as u8
+  //  - the raw image data as BGRA, width * height * 4 bytes.
+  size_t bufferCapacity = 4 + width * height * 4;
+  UniquePtr<uint8_t[]> fileBuf = MakeUnique<uint8_t[]>(bufferCapacity);
+  fileBuf[0] = uint8_t(width);
+  fileBuf[1] = uint8_t(height);
+  fileBuf[2] = uint8_t(mozilla::gfx::SurfaceFormat::B8G8R8A8);
+
+  // Clear all bits to ensure in nsIconDecoder we assume we are already color
+  // managed and premultiplied.
+  fileBuf[3] = 0;
+
+  uint8_t* imageBuf = &fileBuf[4];
+
+  // Create a CGBitmapContext around imageBuf and draw iconImage to it.
+  // This gives us the image data in the format we want: BGRA, four bytes per
+  // pixel, in host endianness, with premultiplied alpha.
+  CGColorSpaceRef cs = CGColorSpaceCreateDeviceRGB();
+  CGContextRef ctx =
+      CGBitmapContextCreate(imageBuf, width, height, 8 /* bitsPerComponent */, width * 4, cs,
+                            kCGBitmapByteOrder32Host | kCGImageAlphaPremultipliedFirst);
+  CGColorSpaceRelease(cs);
+
+  NSGraphicsContext* oldContext = [NSGraphicsContext currentContext];
+  [NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithGraphicsPort:ctx
+                                                                                  flipped:NO]];
+
+  [iconImage drawInRect:NSMakeRect(0, 0, width, height)];
+
+  [NSGraphicsContext setCurrentContext:oldContext];
+
+  CGContextRelease(ctx);
+
+  // Now, create a pipe and stuff our data into it
+  nsCOMPtr<nsIInputStream> inStream;
+  nsCOMPtr<nsIOutputStream> outStream;
+  NS_NewPipe(getter_AddRefs(inStream), getter_AddRefs(outStream), bufferCapacity, bufferCapacity,
+             aNonBlocking);
+
+  uint32_t written;
+  rv = outStream->Write((char*)fileBuf.get(), bufferCapacity, &written);
+  if (NS_SUCCEEDED(rv)) {
+    NS_IF_ADDREF(*_retval = inStream);
+  }
+
+  // Drop notification callbacks to prevent cycles.
+  mCallbacks = nullptr;
+
+  return NS_OK;
+
+  NS_OBJC_END_TRY_BLOCK_RETURN(NS_ERROR_FAILURE);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadFlags(uint32_t* aLoadAttributes) {
+  return mPump->GetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadFlags(uint32_t aLoadAttributes) {
+  return mPump->SetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetTRRMode(nsIRequest::TRRMode* aTRRMode) { return GetTRRModeImpl(aTRRMode); }
+
+NS_IMETHODIMP
+nsIconChannel::SetTRRMode(nsIRequest::TRRMode aTRRMode) { return SetTRRModeImpl(aTRRMode); }
+
+NS_IMETHODIMP
+nsIconChannel::GetIsDocument(bool* aIsDocument) {
+  return NS_GetIsDocumentChannel(this, aIsDocument);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentType(nsACString& aContentType) {
+  aContentType.AssignLiteral(IMAGE_ICON_MS);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentType(const nsACString& aContentType) {
+  // It doesn't make sense to set the content-type on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentCharset(nsACString& aContentCharset) {
+  aContentCharset.AssignLiteral(IMAGE_ICON_MS);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentCharset(const nsACString& aContentCharset) {
+  // It doesn't make sense to set the content-type on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDisposition(uint32_t* aContentDisposition) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentDisposition(uint32_t aContentDisposition) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDispositionFilename(nsAString& aContentDispositionFilename) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentDispositionFilename(const nsAString& aContentDispositionFilename) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDispositionHeader(nsACString& aContentDispositionHeader) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentLength(int64_t* aContentLength) {
+  *aContentLength = 0;
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentLength(int64_t aContentLength) {
+  MOZ_ASSERT_UNREACHABLE("nsIconChannel::SetContentLength");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadGroup(nsILoadGroup** aLoadGroup) {
+  *aLoadGroup = mLoadGroup;
+  NS_IF_ADDREF(*aLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadGroup(nsILoadGroup* aLoadGroup) {
+  mLoadGroup = aLoadGroup;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetOwner(nsISupports** aOwner) {
+  *aOwner = mOwner.get();
+  NS_IF_ADDREF(*aOwner);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOwner(nsISupports* aOwner) {
+  mOwner = aOwner;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadInfo(nsILoadInfo** aLoadInfo) {
+  NS_IF_ADDREF(*aLoadInfo = mLoadInfo);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadInfo(nsILoadInfo* aLoadInfo) {
+  MOZ_RELEASE_ASSERT(aLoadInfo, "loadinfo can't be null");
+  mLoadInfo = aLoadInfo;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetNotificationCallbacks(nsIInterfaceRequestor** aNotificationCallbacks) {
+  *aNotificationCallbacks = mCallbacks.get();
+  NS_IF_ADDREF(*aNotificationCallbacks);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetNotificationCallbacks(nsIInterfaceRequestor* aNotificationCallbacks) {
+  mCallbacks = aNotificationCallbacks;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetSecurityInfo(nsITransportSecurityInfo** aSecurityInfo) {
+  *aSecurityInfo = nullptr;
+  return NS_OK;
+}
diff --git a/image/decoders/icon/moz.build b/image/decoders/icon/moz.build
new file mode 100644
index 0000000000..96cf951b3b
--- /dev/null
+++ b/image/decoders/icon/moz.build
@@ -0,0 +1,39 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+UNIFIED_SOURCES += [
+    "nsIconProtocolHandler.cpp",
+    "nsIconURI.cpp",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+FINAL_LIBRARY = "xul"
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+EXPORTS += [
+    "nsIconURI.h",
+]
+
+platform = None
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
+    platform = "gtk"
+
+if CONFIG["OS_ARCH"] == "WINNT":
+    platform = "win"
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
+    platform = "mac"
+
+if CONFIG["OS_TARGET"] == "Android":
+    platform = "android"
+
+if platform:
+    LOCAL_INCLUDES += [platform]
diff --git a/image/decoders/icon/nsIconProtocolHandler.cpp b/image/decoders/icon/nsIconProtocolHandler.cpp
new file mode 100644
index 0000000000..9334f908db
--- /dev/null
+++ b/image/decoders/icon/nsIconProtocolHandler.cpp
@@ -0,0 +1,68 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIconProtocolHandler.h"
+
+#include "nsIconChannel.h"
+#include "nsIconURI.h"
+#include "nsCRT.h"
+#include "nsCOMPtr.h"
+#include "nsNetCID.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+nsIconProtocolHandler::nsIconProtocolHandler() {}
+
+nsIconProtocolHandler::~nsIconProtocolHandler() {}
+
+NS_IMPL_ISUPPORTS(nsIconProtocolHandler, nsIProtocolHandler,
+                  nsISupportsWeakReference)
+
+///////////////////////////////////////////////////////////////////////////////
+// nsIProtocolHandler methods:
+
+NS_IMETHODIMP
+nsIconProtocolHandler::GetScheme(nsACString& result) {
+  result = "moz-icon";
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::AllowPort(int32_t port, const char* scheme,
+                                 bool* _retval) {
+  // don't override anything.
+  *_retval = false;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconProtocolHandler::NewChannel(nsIURI* url, nsILoadInfo* aLoadInfo,
+                                  nsIChannel** result) {
+  NS_ENSURE_ARG_POINTER(url);
+  nsIconChannel* channel = new nsIconChannel;
+  if (!channel) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+  NS_ADDREF(channel);
+
+  nsresult rv = channel->Init(url);
+  if (NS_FAILED(rv)) {
+    NS_RELEASE(channel);
+    return rv;
+  }
+
+  // set the loadInfo on the new channel
+  rv = channel->SetLoadInfo(aLoadInfo);
+  if (NS_FAILED(rv)) {
+    NS_RELEASE(channel);
+    return rv;
+  }
+
+  *result = channel;
+  return NS_OK;
+}
+
+////////////////////////////////////////////////////////////////////////////////
diff --git a/image/decoders/icon/nsIconProtocolHandler.h b/image/decoders/icon/nsIconProtocolHandler.h
new file mode 100644
index 0000000000..63843eaa4b
--- /dev/null
+++ b/image/decoders/icon/nsIconProtocolHandler.h
@@ -0,0 +1,25 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_icon_nsIconProtocolHandler_h
+#define mozilla_image_decoders_icon_nsIconProtocolHandler_h
+
+#include "nsWeakReference.h"
+#include "nsIProtocolHandler.h"
+
+class nsIconProtocolHandler : public nsIProtocolHandler,
+                              public nsSupportsWeakReference {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIPROTOCOLHANDLER
+
+  // nsIconProtocolHandler methods:
+  nsIconProtocolHandler();
+
+ protected:
+  virtual ~nsIconProtocolHandler();
+};
+
+#endif  // mozilla_image_decoders_icon_nsIconProtocolHandler_h
diff --git a/image/decoders/icon/nsIconURI.cpp b/image/decoders/icon/nsIconURI.cpp
new file mode 100644
index 0000000000..d917337bf9
--- /dev/null
+++ b/image/decoders/icon/nsIconURI.cpp
@@ -0,0 +1,654 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set sw=2 sts=2 ts=2 et tw=80:
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIconURI.h"
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/ipc/URIUtils.h"
+#include "mozilla/Sprintf.h"
+
+#include "nsIClassInfoImpl.h"
+#include "nsIIOService.h"
+#include "nsISerializable.h"
+#include "nsIObjectInputStream.h"
+#include "nsIObjectOutputStream.h"
+#include "nsIURL.h"
+#include "nsNetUtil.h"
+#include "plstr.h"
+#include "nsCRT.h"
+#include <stdlib.h>
+
+using namespace mozilla;
+using namespace mozilla::ipc;
+
+#define DEFAULT_IMAGE_SIZE 16
+
+#if defined(MAX_PATH)
+#  define SANE_FILE_NAME_LEN MAX_PATH
+#elif defined(PATH_MAX)
+#  define SANE_FILE_NAME_LEN PATH_MAX
+#else
+#  define SANE_FILE_NAME_LEN 1024
+#endif
+
+static NS_DEFINE_CID(kThisIconURIImplementationCID,
+                     NS_THIS_ICONURI_IMPLEMENTATION_CID);
+
+static const char* const kSizeStrings[] = {"button", "toolbar", "toolbarsmall",
+                                           "menu",   "dnd",     "dialog"};
+
+static const char* const kStateStrings[] = {"normal", "disabled"};
+
+////////////////////////////////////////////////////////////////////////////////
+
+NS_IMPL_CLASSINFO(nsMozIconURI, nullptr, nsIClassInfo::THREADSAFE,
+                  NS_ICONURI_CID)
+// Empty CI getter. We only need nsIClassInfo for Serialization
+NS_IMPL_CI_INTERFACE_GETTER0(nsMozIconURI)
+
+nsMozIconURI::nsMozIconURI()
+    : mSize(DEFAULT_IMAGE_SIZE), mIconSize(-1), mIconState(-1) {}
+
+nsMozIconURI::~nsMozIconURI() {}
+
+NS_IMPL_ADDREF(nsMozIconURI)
+NS_IMPL_RELEASE(nsMozIconURI)
+
+NS_INTERFACE_MAP_BEGIN(nsMozIconURI)
+  if (aIID.Equals(kThisIconURIImplementationCID)) {
+    foundInterface = static_cast<nsIURI*>(this);
+  } else
+    NS_INTERFACE_MAP_ENTRY(nsIMozIconURI)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIURI)
+  NS_INTERFACE_MAP_ENTRY(nsIURI)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsINestedURI, mIconURL)
+  NS_INTERFACE_MAP_ENTRY(nsISerializable)
+  NS_IMPL_QUERY_CLASSINFO(nsMozIconURI)
+NS_INTERFACE_MAP_END
+
+#define MOZICON_SCHEME "moz-icon:"
+#define MOZICON_SCHEME_LEN (sizeof(MOZICON_SCHEME) - 1)
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIURI methods:
+
+NS_IMETHODIMP
+nsMozIconURI::GetSpec(nsACString& aSpec) {
+  aSpec = MOZICON_SCHEME;
+
+  if (mIconURL) {
+    nsAutoCString fileIconSpec;
+    nsresult rv = mIconURL->GetSpec(fileIconSpec);
+    NS_ENSURE_SUCCESS(rv, rv);
+    aSpec += fileIconSpec;
+  } else if (!mStockIcon.IsEmpty()) {
+    aSpec += "//stock/";
+    aSpec += mStockIcon;
+  } else {
+    aSpec += "//";
+    aSpec += mFileName;
+  }
+
+  aSpec += "?size=";
+  if (mIconSize >= 0) {
+    aSpec += kSizeStrings[mIconSize];
+  } else {
+    char buf[20];
+    SprintfLiteral(buf, "%d", mSize);
+    aSpec.Append(buf);
+  }
+
+  if (mIconState >= 0) {
+    aSpec += "&state=";
+    aSpec += kStateStrings[mIconState];
+  }
+
+  if (!mContentType.IsEmpty()) {
+    aSpec += "&contentType=";
+    aSpec += mContentType.get();
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetSpecIgnoringRef(nsACString& result) { return GetSpec(result); }
+
+NS_IMETHODIMP
+nsMozIconURI::GetDisplaySpec(nsACString& aUnicodeSpec) {
+  return GetSpec(aUnicodeSpec);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetDisplayHostPort(nsACString& aUnicodeHostPort) {
+  return GetHostPort(aUnicodeHostPort);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetDisplayHost(nsACString& aUnicodeHost) {
+  return GetHost(aUnicodeHost);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetDisplayPrePath(nsACString& aPrePath) {
+  return GetPrePath(aPrePath);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetHasRef(bool* result) {
+  *result = false;
+  return NS_OK;
+}
+
+NS_IMPL_NSIURIMUTATOR_ISUPPORTS(nsMozIconURI::Mutator, nsIURISetters,
+                                nsIURIMutator, nsISerializable)
+
+NS_IMETHODIMP
+nsMozIconURI::Mutate(nsIURIMutator** aMutator) {
+  RefPtr<nsMozIconURI::Mutator> mutator = new nsMozIconURI::Mutator();
+  nsresult rv = mutator->InitFromURI(this);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+  mutator.forget(aMutator);
+  return NS_OK;
+}
+
+// helper function for parsing out attributes like size, and contentType
+// from the icon url.
+// takes a string like ?size=32&contentType=text/html and returns a new string
+// containing just the attribute value. i.e you could pass in this string with
+// an attribute name of 'size=', this will return 32
+// Assumption: attribute pairs in the string are separated by '&'.
+static void extractAttributeValue(const char* aSearchString,
+                                  const char* aAttributeName,
+                                  nsCString& aResult) {
+  aResult.Truncate();
+
+  if (aSearchString && aAttributeName) {
+    // search the string for attributeName
+    uint32_t attributeNameSize = strlen(aAttributeName);
+    const char* startOfAttribute = PL_strcasestr(aSearchString, aAttributeName);
+    if (startOfAttribute &&
+        (*(startOfAttribute - 1) == '?' || *(startOfAttribute - 1) == '&')) {
+      startOfAttribute += attributeNameSize;  // skip over the attributeName
+      // is there something after the attribute name
+      if (*startOfAttribute) {
+        const char* endofAttribute = strchr(startOfAttribute, '&');
+        if (endofAttribute) {
+          aResult.Assign(Substring(startOfAttribute, endofAttribute));
+        } else {
+          aResult.Assign(startOfAttribute);
+        }
+      }  // if we have a attribute value
+    }    // if we have a attribute name
+  }      // if we got non-null search string and attribute name values
+}
+
+nsresult nsMozIconURI::SetSpecInternal(const nsACString& aSpec) {
+  // Reset everything to default values.
+  mIconURL = nullptr;
+  mSize = DEFAULT_IMAGE_SIZE;
+  mContentType.Truncate();
+  mFileName.Truncate();
+  mStockIcon.Truncate();
+  mIconSize = -1;
+  mIconState = -1;
+
+  nsAutoCString iconSpec(aSpec);
+  if (!Substring(iconSpec, 0, MOZICON_SCHEME_LEN)
+           .EqualsLiteral(MOZICON_SCHEME) ||
+      (!Substring(iconSpec, MOZICON_SCHEME_LEN, 7).EqualsLiteral("file://") &&
+       // Checking for the leading '//' will match both the '//stock/' and
+       // '//.foo' cases:
+       !Substring(iconSpec, MOZICON_SCHEME_LEN, 2).EqualsLiteral("//"))) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  int32_t questionMarkPos = iconSpec.Find("?");
+  if (questionMarkPos != -1 &&
+      static_cast<int32_t>(iconSpec.Length()) > (questionMarkPos + 1)) {
+    extractAttributeValue(iconSpec.get(), "contentType=", mContentType);
+
+    nsAutoCString sizeString;
+    extractAttributeValue(iconSpec.get(), "size=", sizeString);
+    if (!sizeString.IsEmpty()) {
+      const char* sizeStr = sizeString.get();
+      for (uint32_t i = 0; i < ArrayLength(kSizeStrings); i++) {
+        if (nsCRT::strcasecmp(sizeStr, kSizeStrings[i]) == 0) {
+          mIconSize = i;
+          break;
+        }
+      }
+
+      int32_t sizeValue = atoi(sizeString.get());
+      if (sizeValue > 0) {
+        mSize = sizeValue;
+      }
+    }
+
+    nsAutoCString stateString;
+    extractAttributeValue(iconSpec.get(), "state=", stateString);
+    if (!stateString.IsEmpty()) {
+      const char* stateStr = stateString.get();
+      for (uint32_t i = 0; i < ArrayLength(kStateStrings); i++) {
+        if (nsCRT::strcasecmp(stateStr, kStateStrings[i]) == 0) {
+          mIconState = i;
+          break;
+        }
+      }
+    }
+  }
+
+  int32_t pathLength = iconSpec.Length() - MOZICON_SCHEME_LEN;
+  if (questionMarkPos != -1) {
+    pathLength = questionMarkPos - MOZICON_SCHEME_LEN;
+  }
+  if (pathLength < 3) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  nsAutoCString iconPath(Substring(iconSpec, MOZICON_SCHEME_LEN, pathLength));
+
+  // Icon URI path can have three forms:
+  // (1) //stock/<icon-identifier>
+  // (2) //<some dummy file with an extension>
+  // (3) a valid URL
+
+  if (!strncmp("//stock/", iconPath.get(), 8)) {
+    mStockIcon.Assign(Substring(iconPath, 8));
+    // An icon identifier must always be specified.
+    if (mStockIcon.IsEmpty()) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    return NS_OK;
+  }
+
+  if (StringBeginsWith(iconPath, "//"_ns)) {
+    // Sanity check this supposed dummy file name.
+    if (iconPath.Length() > SANE_FILE_NAME_LEN) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    iconPath.Cut(0, 2);
+    mFileName.Assign(iconPath);
+  }
+
+  nsresult rv;
+  nsCOMPtr<nsIIOService> ioService(do_GetService(NS_IOSERVICE_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIURI> uri;
+  ioService->NewURI(iconPath, nullptr, nullptr, getter_AddRefs(uri));
+  mIconURL = do_QueryInterface(uri);
+  if (mIconURL) {
+    // The inner URI should be a 'file:' one. If not, bail.
+    if (!mIconURL->SchemeIs("file")) {
+      return NS_ERROR_MALFORMED_URI;
+    }
+    mFileName.Truncate();
+  } else if (mFileName.IsEmpty()) {
+    return NS_ERROR_MALFORMED_URI;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPrePath(nsACString& prePath) {
+  prePath = MOZICON_SCHEME;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetScheme(nsACString& aScheme) {
+  aScheme = "moz-icon";
+  return NS_OK;
+}
+
+nsresult nsMozIconURI::SetScheme(const nsACString& aScheme) {
+  // doesn't make sense to set the scheme of a moz-icon URL
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetUsername(nsACString& aUsername) { return NS_ERROR_FAILURE; }
+
+nsresult nsMozIconURI::SetUsername(const nsACString& aUsername) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPassword(nsACString& aPassword) { return NS_ERROR_FAILURE; }
+
+nsresult nsMozIconURI::SetPassword(const nsACString& aPassword) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetUserPass(nsACString& aUserPass) { return NS_ERROR_FAILURE; }
+
+nsresult nsMozIconURI::SetUserPass(const nsACString& aUserPass) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetHostPort(nsACString& aHostPort) { return NS_ERROR_FAILURE; }
+
+nsresult nsMozIconURI::SetHostPort(const nsACString& aHostPort) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetHost(nsACString& aHost) { return NS_ERROR_FAILURE; }
+
+nsresult nsMozIconURI::SetHost(const nsACString& aHost) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetPort(int32_t* aPort) { return NS_ERROR_FAILURE; }
+
+nsresult nsMozIconURI::SetPort(int32_t aPort) { return NS_ERROR_FAILURE; }
+
+NS_IMETHODIMP
+nsMozIconURI::GetPathQueryRef(nsACString& aPath) {
+  aPath.Truncate();
+  return NS_OK;
+}
+
+nsresult nsMozIconURI::SetPathQueryRef(const nsACString& aPath) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetFilePath(nsACString& aFilePath) {
+  aFilePath.Truncate();
+  return NS_OK;
+}
+
+nsresult nsMozIconURI::SetFilePath(const nsACString& aFilePath) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetQuery(nsACString& aQuery) {
+  aQuery.Truncate();
+  return NS_OK;
+}
+
+nsresult nsMozIconURI::SetQuery(const nsACString& aQuery) {
+  return NS_ERROR_FAILURE;
+}
+
+nsresult nsMozIconURI::SetQueryWithEncoding(const nsACString& aQuery,
+                                            const Encoding* aEncoding) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetRef(nsACString& aRef) {
+  aRef.Truncate();
+  return NS_OK;
+}
+
+nsresult nsMozIconURI::SetRef(const nsACString& aRef) {
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::Equals(nsIURI* other, bool* result) {
+  *result = false;
+  NS_ENSURE_ARG_POINTER(other);
+  MOZ_ASSERT(result, "null pointer");
+
+  nsAutoCString spec1;
+  nsAutoCString spec2;
+
+  nsresult rv = GetSpec(spec1);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = other->GetSpec(spec2);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (!nsCRT::strcasecmp(spec1.get(), spec2.get())) {
+    *result = true;
+  } else {
+    *result = false;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::EqualsExceptRef(nsIURI* other, bool* result) {
+  // GetRef/SetRef not supported by nsMozIconURI, so
+  // EqualsExceptRef() is the same as Equals().
+  return Equals(other, result);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::SchemeIs(const char* aScheme, bool* aEquals) {
+  MOZ_ASSERT(aEquals, "null pointer");
+  if (!aScheme) {
+    *aEquals = false;
+    return NS_OK;
+  }
+
+  *aEquals = nsCRT::strcasecmp("moz-icon", aScheme) == 0;
+  return NS_OK;
+}
+
+nsresult nsMozIconURI::Clone(nsIURI** result) {
+  nsCOMPtr<nsIURL> newIconURL;
+  if (mIconURL) {
+    newIconURL = mIconURL;
+  }
+
+  RefPtr<nsMozIconURI> uri = new nsMozIconURI();
+  newIconURL.swap(uri->mIconURL);
+  uri->mSize = mSize;
+  uri->mContentType = mContentType;
+  uri->mFileName = mFileName;
+  uri->mStockIcon = mStockIcon;
+  uri->mIconSize = mIconSize;
+  uri->mIconState = mIconState;
+  uri.forget(result);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::Resolve(const nsACString& relativePath, nsACString& result) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetAsciiSpec(nsACString& aSpecA) { return GetSpec(aSpecA); }
+
+NS_IMETHODIMP
+nsMozIconURI::GetAsciiHostPort(nsACString& aHostPortA) {
+  return GetHostPort(aHostPortA);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetAsciiHost(nsACString& aHostA) { return GetHost(aHostA); }
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIIconUri methods:
+
+NS_IMETHODIMP
+nsMozIconURI::GetIconURL(nsIURL** aFileUrl) {
+  *aFileUrl = mIconURL;
+  NS_IF_ADDREF(*aFileUrl);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetImageSize(uint32_t* aImageSize)
+// measured by # of pixels in a row. defaults to 16.
+{
+  *aImageSize = mSize;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetContentType(nsACString& aContentType) {
+  aContentType = mContentType;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetFileExtension(nsACString& aFileExtension) {
+  // First, try to get the extension from mIconURL if we have one
+  if (mIconURL) {
+    nsAutoCString fileExt;
+    if (NS_SUCCEEDED(mIconURL->GetFileExtension(fileExt))) {
+      if (!fileExt.IsEmpty()) {
+        // unfortunately, this code doesn't give us the required '.' in
+        // front of the extension so we have to do it ourselves.
+        aFileExtension.Assign('.');
+        aFileExtension.Append(fileExt);
+      }
+    }
+    return NS_OK;
+  }
+
+  if (!mFileName.IsEmpty()) {
+    // truncate the extension out of the file path...
+    const char* chFileName = mFileName.get();  // get the underlying buffer
+    const char* fileExt = strrchr(chFileName, '.');
+    if (!fileExt) {
+      return NS_OK;
+    }
+    aFileExtension = fileExt;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetStockIcon(nsACString& aStockIcon) {
+  aStockIcon = mStockIcon;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetIconSize(nsACString& aSize) {
+  if (mIconSize >= 0) {
+    aSize = kSizeStrings[mIconSize];
+  } else {
+    aSize.Truncate();
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetIconState(nsACString& aState) {
+  if (mIconState >= 0) {
+    aState = kStateStrings[mIconState];
+  } else {
+    aState.Truncate();
+  }
+  return NS_OK;
+}
+
+void nsMozIconURI::Serialize(URIParams& aParams) {
+  IconURIParams params;
+
+  if (mIconURL) {
+    URIParams iconURLParams;
+    SerializeURI(mIconURL, iconURLParams);
+    if (iconURLParams.type() == URIParams::T__None) {
+      // Serialization failed, bail.
+      return;
+    }
+
+    params.uri() = Some(std::move(iconURLParams));
+  } else {
+    params.uri() = Nothing();
+  }
+
+  params.size() = mSize;
+  params.fileName() = mFileName;
+  params.stockIcon() = mStockIcon;
+  params.iconSize() = mIconSize;
+  params.iconState() = mIconState;
+
+  aParams = params;
+}
+
+bool nsMozIconURI::Deserialize(const URIParams& aParams) {
+  if (aParams.type() != URIParams::TIconURIParams) {
+    MOZ_ASSERT_UNREACHABLE("Received unknown URI from other process!");
+    return false;
+  }
+
+  const IconURIParams& params = aParams.get_IconURIParams();
+  if (params.uri().isSome()) {
+    nsCOMPtr<nsIURI> uri = DeserializeURI(params.uri().ref());
+    mIconURL = do_QueryInterface(uri);
+    if (!mIconURL) {
+      MOZ_ASSERT_UNREACHABLE("bad nsIURI passed");
+      return false;
+    }
+  }
+
+  mSize = params.size();
+  mContentType = params.contentType();
+  mFileName = params.fileName();
+  mStockIcon = params.stockIcon();
+
+  if (params.iconSize() < -1 ||
+      params.iconSize() >= (int32_t)ArrayLength(kSizeStrings)) {
+    return false;
+  }
+  mIconSize = params.iconSize();
+
+  if (params.iconState() < -1 ||
+      params.iconState() >= (int32_t)ArrayLength(kStateStrings)) {
+    return false;
+  }
+  mIconState = params.iconState();
+
+  return true;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetInnerURI(nsIURI** aURI) {
+  nsCOMPtr<nsIURI> iconURL = mIconURL;
+  if (!iconURL) {
+    *aURI = nullptr;
+    return NS_ERROR_FAILURE;
+  }
+
+  iconURL.forget(aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsMozIconURI::GetInnermostURI(nsIURI** aURI) {
+  return NS_ImplGetInnermostURI(this, aURI);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::Read(nsIObjectInputStream* aStream) {
+  MOZ_ASSERT_UNREACHABLE("Use nsIURIMutator.read() instead");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+nsresult nsMozIconURI::ReadPrivate(nsIObjectInputStream* aStream) {
+  nsAutoCString spec;
+  nsresult rv = aStream->ReadCString(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return SetSpecInternal(spec);
+}
+
+NS_IMETHODIMP
+nsMozIconURI::Write(nsIObjectOutputStream* aStream) {
+  nsAutoCString spec;
+  nsresult rv = GetSpec(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return aStream->WriteStringZ(spec.get());
+}
diff --git a/image/decoders/icon/nsIconURI.h b/image/decoders/icon/nsIconURI.h
new file mode 100644
index 0000000000..1f55bc686c
--- /dev/null
+++ b/image/decoders/icon/nsIconURI.h
@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_icon_nsIconURI_h
+#define mozilla_image_decoders_icon_nsIconURI_h
+
+#include "nsIIconURI.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsINestedURI.h"
+#include "nsIURIMutator.h"
+#include "nsISerializable.h"
+
+#define NS_THIS_ICONURI_IMPLEMENTATION_CID           \
+  { /* 0b9bb0c2-fee6-470b-b9b9-9fd9462b5e19 */       \
+    0x5c3e417f, 0xb686, 0x4105, {                    \
+      0x86, 0xe7, 0xf9, 0x1b, 0xac, 0x97, 0x4d, 0x5c \
+    }                                                \
+  }
+
+namespace mozilla {
+class Encoding;
+}
+
+class nsMozIconURI final : public nsIMozIconURI,
+                           public nsINestedURI,
+                           public nsISerializable {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIURI
+  NS_DECL_NSIMOZICONURI
+  NS_DECL_NSINESTEDURI
+  NS_DECL_NSISERIALIZABLE
+
+ protected:
+  nsMozIconURI();
+  virtual ~nsMozIconURI();
+  nsCOMPtr<nsIURL> mIconURL;  // a URL that we want the icon for
+  uint32_t mSize;  // the # of pixels in a row that we want for this image.
+                   // Typically 16, 32, 128, etc.
+  nsCString mContentType;  // optional field explicitly specifying the content
+                           // type
+  nsCString mFileName;  // for if we don't have an actual file path, we're just
+                        // given a filename with an extension
+  nsCString mStockIcon;
+  int32_t mIconSize;   // -1 if not specified, otherwise index into
+                       // kSizeStrings
+  int32_t mIconState;  // -1 if not specified, otherwise index into
+                       // kStateStrings
+
+ private:
+  nsresult Clone(nsIURI** aURI);
+  nsresult SetSpecInternal(const nsACString& input);
+  nsresult SetScheme(const nsACString& input);
+  nsresult SetUserPass(const nsACString& input);
+  nsresult SetUsername(const nsACString& input);
+  nsresult SetPassword(const nsACString& input);
+  nsresult SetHostPort(const nsACString& aValue);
+  nsresult SetHost(const nsACString& input);
+  nsresult SetPort(int32_t port);
+  nsresult SetPathQueryRef(const nsACString& input);
+  nsresult SetRef(const nsACString& input);
+  nsresult SetFilePath(const nsACString& input);
+  nsresult SetQuery(const nsACString& input);
+  nsresult SetQueryWithEncoding(const nsACString& input,
+                                const mozilla::Encoding* encoding);
+  nsresult ReadPrivate(nsIObjectInputStream* stream);
+  bool Deserialize(const mozilla::ipc::URIParams&);
+
+ public:
+  class Mutator final : public nsIURIMutator,
+                        public BaseURIMutator<nsMozIconURI>,
+                        public nsISerializable {
+    NS_DECL_ISUPPORTS
+    NS_FORWARD_SAFE_NSIURISETTERS_RET(mURI)
+
+    NS_IMETHOD
+    Write(nsIObjectOutputStream* aOutputStream) override {
+      return NS_ERROR_NOT_IMPLEMENTED;
+    }
+
+    [[nodiscard]] NS_IMETHOD Read(nsIObjectInputStream* aStream) override {
+      return InitFromInputStream(aStream);
+    }
+
+    NS_IMETHOD Deserialize(const mozilla::ipc::URIParams& aParams) override {
+      return InitFromIPCParams(aParams);
+    }
+
+    NS_IMETHOD Finalize(nsIURI** aURI) override {
+      mURI.forget(aURI);
+      return NS_OK;
+    }
+
+    NS_IMETHOD SetSpec(const nsACString& aSpec,
+                       nsIURIMutator** aMutator) override {
+      if (aMutator) {
+        nsCOMPtr<nsIURIMutator> mutator = this;
+        mutator.forget(aMutator);
+      }
+      return InitFromSpec(aSpec);
+    }
+
+    explicit Mutator() {}
+
+   private:
+    virtual ~Mutator() {}
+
+    friend class nsMozIconURI;
+  };
+
+  friend BaseURIMutator<nsMozIconURI>;
+};
+
+#endif  // mozilla_image_decoders_icon_nsIconURI_h
diff --git a/image/decoders/icon/win/moz.build b/image/decoders/icon/win/moz.build
new file mode 100644
index 0000000000..c4472f89ac
--- /dev/null
+++ b/image/decoders/icon/win/moz.build
@@ -0,0 +1,21 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+SOURCES += [
+    "nsIconChannel.cpp",
+]
+
+EXPORTS += [
+    "nsIconChannel.h",
+]
+
+LOCAL_INCLUDES += [
+    "/image",
+]
+
+FINAL_LIBRARY = "xul"
+
+include("/ipc/chromium/chromium-config.mozbuild")
diff --git a/image/decoders/icon/win/nsIconChannel.cpp b/image/decoders/icon/win/nsIconChannel.cpp
new file mode 100644
index 0000000000..247e1aa822
--- /dev/null
+++ b/image/decoders/icon/win/nsIconChannel.cpp
@@ -0,0 +1,1007 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/SyncRunnable.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/UniquePtrExtensions.h"
+#include "mozilla/WindowsProcessMitigations.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/ipc/ByteBuf.h"
+
+#include "nsComponentManagerUtils.h"
+#include "nsIconChannel.h"
+#include "nsIIconURI.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsString.h"
+#include "nsReadableUtils.h"
+#include "nsMimeTypes.h"
+#include "nsIURL.h"
+#include "nsIPipe.h"
+#include "nsNetCID.h"
+#include "nsIFile.h"
+#include "nsIFileURL.h"
+#include "nsIIconURI.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIMIMEService.h"
+#include "nsCExternalHandlerService.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsProxyRelease.h"
+#include "nsContentSecurityManager.h"
+#include "nsContentUtils.h"
+#include "nsNetUtil.h"
+#include "nsThreadUtils.h"
+
+#include "Decoder.h"
+#include "DecodePool.h"
+
+// we need windows.h to read out registry information...
+#include <windows.h>
+#include <shellapi.h>
+#include <shlobj.h>
+#include <objbase.h>
+#include <wchar.h>
+
+using namespace mozilla;
+using namespace mozilla::image;
+
+using mozilla::ipc::ByteBuf;
+
+struct ICONFILEHEADER {
+  uint16_t ifhReserved;
+  uint16_t ifhType;
+  uint16_t ifhCount;
+};
+
+struct ICONENTRY {
+  int8_t ieWidth;
+  int8_t ieHeight;
+  uint8_t ieColors;
+  uint8_t ieReserved;
+  uint16_t iePlanes;
+  uint16_t ieBitCount;
+  uint32_t ieSizeImage;
+  uint32_t ieFileOffset;
+};
+
+struct IconPathInfo {
+  nsCOMPtr<nsIFile> localFile;
+  nsAutoString filePath;
+  UINT infoFlags = 0;
+};
+
+using HIconPromise = MozPromise<HICON, nsresult, true>;
+
+static UINT GetSizeInfoFlag(uint32_t aDesiredImageSize) {
+  return aDesiredImageSize > 16 ? SHGFI_SHELLICONSIZE : SHGFI_SMALLICON;
+}
+
+static nsresult ExtractIconInfoFromUrl(nsIURI* aUrl, nsIFile** aLocalFile,
+                                       uint32_t* aDesiredImageSize,
+                                       nsCString& aContentType,
+                                       nsCString& aFileExtension) {
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMozIconURI> iconURI(do_QueryInterface(aUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  iconURI->GetImageSize(aDesiredImageSize);
+  iconURI->GetContentType(aContentType);
+  iconURI->GetFileExtension(aFileExtension);
+
+  nsCOMPtr<nsIURL> url;
+  rv = iconURI->GetIconURL(getter_AddRefs(url));
+  if (NS_FAILED(rv) || !url) return NS_OK;
+
+  nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(url, &rv);
+  if (NS_FAILED(rv) || !fileURL) return NS_OK;
+
+  nsCOMPtr<nsIFile> file;
+  rv = fileURL->GetFile(getter_AddRefs(file));
+  if (NS_FAILED(rv) || !file) return NS_OK;
+
+  return file->Clone(aLocalFile);
+}
+
+static nsresult ExtractIconPathInfoFromUrl(nsIURI* aUrl,
+                                           IconPathInfo* aIconPathInfo) {
+  nsCString contentType;
+  nsCString fileExt;
+  nsCOMPtr<nsIFile> localFile;  // file we want an icon for
+  uint32_t desiredImageSize;
+  nsresult rv = ExtractIconInfoFromUrl(aUrl, getter_AddRefs(localFile),
+                                       &desiredImageSize, contentType, fileExt);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // if the file exists, we are going to use it's real attributes...
+  // otherwise we only want to use it for it's extension...
+  UINT infoFlags = SHGFI_ICON;
+
+  bool fileExists = false;
+
+  nsAutoString filePath;
+  CopyASCIItoUTF16(fileExt, filePath);
+  if (localFile) {
+    rv = localFile->Normalize();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    localFile->GetPath(filePath);
+    if (filePath.Length() < 2 || filePath[1] != ':') {
+      return NS_ERROR_MALFORMED_URI;  // UNC
+    }
+
+    if (filePath.Last() == ':') {
+      filePath.Append('\\');
+    } else {
+      localFile->Exists(&fileExists);
+      if (!fileExists) {
+        localFile->GetLeafName(filePath);
+      }
+    }
+  }
+
+  if (!fileExists) {
+    infoFlags |= SHGFI_USEFILEATTRIBUTES;
+  }
+
+  infoFlags |= GetSizeInfoFlag(desiredImageSize);
+
+  // if we have a content type... then use it! but for existing files,
+  // we want to show their real icon.
+  if (!fileExists && !contentType.IsEmpty()) {
+    nsCOMPtr<nsIMIMEService> mimeService(
+        do_GetService(NS_MIMESERVICE_CONTRACTID, &rv));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsAutoCString defFileExt;
+    mimeService->GetPrimaryExtension(contentType, fileExt, defFileExt);
+    // If the mime service does not know about this mime type, we show
+    // the generic icon.
+    // In any case, we need to insert a '.' before the extension.
+    filePath = u"."_ns + NS_ConvertUTF8toUTF16(defFileExt);
+  }
+
+  if (!localFile && !fileExists &&
+      ((filePath.Length() == 1 && filePath.Last() == '.') ||
+       filePath.Length() == 0)) {
+    filePath = u".MozBogusExtensionMoz"_ns;
+  }
+
+  aIconPathInfo->localFile = std::move(localFile);
+  aIconPathInfo->filePath = std::move(filePath);
+  aIconPathInfo->infoFlags = infoFlags;
+
+  return NS_OK;
+}
+
+static bool GetSpecialFolderIcon(nsIFile* aFile, int aFolder, UINT aInfoFlags,
+                                 HICON* aIcon) {
+  if (!aFile) {
+    return false;
+  }
+
+  wchar_t fileNativePath[MAX_PATH];
+  nsAutoString fileNativePathStr;
+  aFile->GetPath(fileNativePathStr);
+  ::GetShortPathNameW(fileNativePathStr.get(), fileNativePath,
+                      ArrayLength(fileNativePath));
+
+  struct IdListDeleter {
+    void operator()(ITEMIDLIST* ptr) { ::CoTaskMemFree(ptr); }
+  };
+
+  UniquePtr<ITEMIDLIST, IdListDeleter> idList;
+  HRESULT hr =
+      ::SHGetSpecialFolderLocation(nullptr, aFolder, getter_Transfers(idList));
+  if (FAILED(hr)) {
+    return false;
+  }
+
+  wchar_t specialNativePath[MAX_PATH];
+  ::SHGetPathFromIDListW(idList.get(), specialNativePath);
+  ::GetShortPathNameW(specialNativePath, specialNativePath,
+                      ArrayLength(specialNativePath));
+
+  if (wcsicmp(fileNativePath, specialNativePath) != 0) {
+    return false;
+  }
+
+  SHFILEINFOW sfi = {};
+  aInfoFlags |= (SHGFI_PIDL | SHGFI_SYSICONINDEX);
+  if (::SHGetFileInfoW((LPCWSTR)(LPCITEMIDLIST)idList.get(), 0, &sfi,
+                       sizeof(sfi), aInfoFlags) == 0) {
+    return false;
+  }
+
+  *aIcon = sfi.hIcon;
+  return true;
+}
+
+static nsresult GetIconHandleFromPathInfo(const IconPathInfo& aPathInfo,
+                                          HICON* aIcon) {
+  MOZ_DIAGNOSTIC_ASSERT(!IsWin32kLockedDown());
+
+  // Is this the "Desktop" folder?
+  if (GetSpecialFolderIcon(aPathInfo.localFile, CSIDL_DESKTOP,
+                           aPathInfo.infoFlags, aIcon)) {
+    return NS_OK;
+  }
+
+  // Is this the "My Documents" folder?
+  if (GetSpecialFolderIcon(aPathInfo.localFile, CSIDL_PERSONAL,
+                           aPathInfo.infoFlags, aIcon)) {
+    return NS_OK;
+  }
+
+  // There are other "Special Folders" and Namespace entities that we
+  // are not fetching icons for, see:
+  // http://msdn.microsoft.com/library/default.asp?url=/library/en-us/
+  //        shellcc/platform/shell/reference/enums/csidl.asp
+  // If we ever need to get them, code to do so would be inserted here.
+
+  // Not a special folder, or something else failed above.
+  SHFILEINFOW sfi = {};
+  if (::SHGetFileInfoW(aPathInfo.filePath.get(), FILE_ATTRIBUTE_ARCHIVE, &sfi,
+                       sizeof(sfi), aPathInfo.infoFlags) != 0) {
+    *aIcon = sfi.hIcon;
+    return NS_OK;
+  }
+
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+// Match stock icons with names
+static mozilla::Maybe<SHSTOCKICONID> GetStockIconIDForName(
+    const nsACString& aStockName) {
+  return aStockName.EqualsLiteral("uac-shield") ? Some(SIID_SHIELD) : Nothing();
+}
+
+// Specific to Vista and above
+static nsresult GetStockHIcon(nsIMozIconURI* aIconURI, HICON* aIcon) {
+  uint32_t desiredImageSize;
+  aIconURI->GetImageSize(&desiredImageSize);
+  nsAutoCString stockIcon;
+  aIconURI->GetStockIcon(stockIcon);
+
+  Maybe<SHSTOCKICONID> stockIconID = GetStockIconIDForName(stockIcon);
+  if (stockIconID.isNothing()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  UINT infoFlags = SHGSI_ICON;
+  infoFlags |= GetSizeInfoFlag(desiredImageSize);
+
+  SHSTOCKICONINFO sii = {0};
+  sii.cbSize = sizeof(sii);
+  HRESULT hr = SHGetStockIconInfo(*stockIconID, infoFlags, &sii);
+  if (FAILED(hr)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  *aIcon = sii.hIcon;
+
+  return NS_OK;
+}
+
+// Given a BITMAPINFOHEADER, returns the size of the color table.
+static int GetColorTableSize(BITMAPINFOHEADER* aHeader) {
+  int colorTableSize = -1;
+
+  // http://msdn.microsoft.com/en-us/library/dd183376%28v=VS.85%29.aspx
+  switch (aHeader->biBitCount) {
+    case 0:
+      colorTableSize = 0;
+      break;
+    case 1:
+      colorTableSize = 2 * sizeof(RGBQUAD);
+      break;
+    case 4:
+    case 8: {
+      // The maximum possible size for the color table is 2**bpp, so check for
+      // that and fail if we're not in those bounds
+      unsigned int maxEntries = 1 << (aHeader->biBitCount);
+      if (aHeader->biClrUsed > 0 && aHeader->biClrUsed <= maxEntries) {
+        colorTableSize = aHeader->biClrUsed * sizeof(RGBQUAD);
+      } else if (aHeader->biClrUsed == 0) {
+        colorTableSize = maxEntries * sizeof(RGBQUAD);
+      }
+      break;
+    }
+    case 16:
+    case 32:
+      // If we have BI_BITFIELDS compression, we would normally need 3 DWORDS
+      // for the bitfields mask which would be stored in the color table;
+      // However, we instead force the bitmap to request data of type BI_RGB so
+      // the color table should be of size 0. Setting aHeader->biCompression =
+      // BI_RGB forces the later call to GetDIBits to return to us BI_RGB data.
+      if (aHeader->biCompression == BI_BITFIELDS) {
+        aHeader->biCompression = BI_RGB;
+      }
+      colorTableSize = 0;
+      break;
+    case 24:
+      colorTableSize = 0;
+      break;
+  }
+
+  if (colorTableSize < 0) {
+    NS_WARNING("Unable to figure out the color table size for this bitmap");
+  }
+
+  return colorTableSize;
+}
+
+// Given a header and a size, creates a freshly allocated BITMAPINFO structure.
+// It is the caller's responsibility to null-check and delete the structure.
+static BITMAPINFO* CreateBitmapInfo(BITMAPINFOHEADER* aHeader,
+                                    size_t aColorTableSize) {
+  BITMAPINFO* bmi = (BITMAPINFO*)::operator new(
+      sizeof(BITMAPINFOHEADER) + aColorTableSize, mozilla::fallible);
+  if (bmi) {
+    memcpy(bmi, aHeader, sizeof(BITMAPINFOHEADER));
+    memset(bmi->bmiColors, 0, aColorTableSize);
+  }
+  return bmi;
+}
+
+static nsresult MakeIconBuffer(HICON aIcon, ByteBuf* aOutBuffer) {
+  nsresult rv = NS_ERROR_FAILURE;
+
+  if (aIcon) {
+    // we got a handle to an icon. Now we want to get a bitmap for the icon
+    // using GetIconInfo....
+    ICONINFO iconInfo;
+    if (GetIconInfo(aIcon, &iconInfo)) {
+      // we got the bitmaps, first find out their size
+      HDC hDC = CreateCompatibleDC(nullptr);  // get a device context for
+                                              // the screen.
+      BITMAPINFOHEADER maskHeader = {sizeof(BITMAPINFOHEADER)};
+      BITMAPINFOHEADER colorHeader = {sizeof(BITMAPINFOHEADER)};
+      int colorTableSize, maskTableSize;
+      if (GetDIBits(hDC, iconInfo.hbmMask, 0, 0, nullptr,
+                    (BITMAPINFO*)&maskHeader, DIB_RGB_COLORS) &&
+          GetDIBits(hDC, iconInfo.hbmColor, 0, 0, nullptr,
+                    (BITMAPINFO*)&colorHeader, DIB_RGB_COLORS) &&
+          maskHeader.biHeight == colorHeader.biHeight &&
+          maskHeader.biWidth == colorHeader.biWidth &&
+          colorHeader.biBitCount > 8 && colorHeader.biSizeImage > 0 &&
+          colorHeader.biWidth >= 0 && colorHeader.biWidth <= 255 &&
+          colorHeader.biHeight >= 0 && colorHeader.biHeight <= 255 &&
+          maskHeader.biSizeImage > 0 &&
+          (colorTableSize = GetColorTableSize(&colorHeader)) >= 0 &&
+          (maskTableSize = GetColorTableSize(&maskHeader)) >= 0) {
+        uint32_t iconSize = sizeof(ICONFILEHEADER) + sizeof(ICONENTRY) +
+                            sizeof(BITMAPINFOHEADER) + colorHeader.biSizeImage +
+                            maskHeader.biSizeImage;
+
+        if (!aOutBuffer->Allocate(iconSize)) {
+          rv = NS_ERROR_OUT_OF_MEMORY;
+        } else {
+          uint8_t* whereTo = aOutBuffer->mData;
+          int howMuch;
+
+          // the data starts with an icon file header
+          ICONFILEHEADER iconHeader;
+          iconHeader.ifhReserved = 0;
+          iconHeader.ifhType = 1;
+          iconHeader.ifhCount = 1;
+          howMuch = sizeof(ICONFILEHEADER);
+          memcpy(whereTo, &iconHeader, howMuch);
+          whereTo += howMuch;
+
+          // followed by the single icon entry
+          ICONENTRY iconEntry;
+          iconEntry.ieWidth = static_cast<int8_t>(colorHeader.biWidth);
+          iconEntry.ieHeight = static_cast<int8_t>(colorHeader.biHeight);
+          iconEntry.ieColors = 0;
+          iconEntry.ieReserved = 0;
+          iconEntry.iePlanes = 1;
+          iconEntry.ieBitCount = colorHeader.biBitCount;
+          iconEntry.ieSizeImage = sizeof(BITMAPINFOHEADER) +
+                                  colorHeader.biSizeImage +
+                                  maskHeader.biSizeImage;
+          iconEntry.ieFileOffset = sizeof(ICONFILEHEADER) + sizeof(ICONENTRY);
+          howMuch = sizeof(ICONENTRY);
+          memcpy(whereTo, &iconEntry, howMuch);
+          whereTo += howMuch;
+
+          // followed by the bitmap info header
+          // (doubling the height because icons have two bitmaps)
+          colorHeader.biHeight *= 2;
+          colorHeader.biSizeImage += maskHeader.biSizeImage;
+          howMuch = sizeof(BITMAPINFOHEADER);
+          memcpy(whereTo, &colorHeader, howMuch);
+          whereTo += howMuch;
+          colorHeader.biHeight /= 2;
+          colorHeader.biSizeImage -= maskHeader.biSizeImage;
+
+          // followed by the XOR bitmap data (colorHeader)
+          // (you'd expect the color table to come here, but it apparently
+          // doesn't)
+          BITMAPINFO* colorInfo =
+              CreateBitmapInfo(&colorHeader, colorTableSize);
+          if (colorInfo &&
+              GetDIBits(hDC, iconInfo.hbmColor, 0, colorHeader.biHeight,
+                        whereTo, colorInfo, DIB_RGB_COLORS)) {
+            whereTo += colorHeader.biSizeImage;
+
+            // and finally the AND bitmap data (maskHeader)
+            BITMAPINFO* maskInfo = CreateBitmapInfo(&maskHeader, maskTableSize);
+            if (maskInfo &&
+                GetDIBits(hDC, iconInfo.hbmMask, 0, maskHeader.biHeight,
+                          whereTo, maskInfo, DIB_RGB_COLORS)) {
+              rv = NS_OK;
+            }  // if we got bitmap bits
+            delete maskInfo;
+          }  // if we got mask bits
+          delete colorInfo;
+        }  // if we allocated the buffer
+      }    // if we got mask size
+
+      DeleteDC(hDC);
+      DeleteObject(iconInfo.hbmColor);
+      DeleteObject(iconInfo.hbmMask);
+    }  // if we got icon info
+    DestroyIcon(aIcon);
+  }  // if we got an hIcon
+
+  return rv;
+}
+
+static nsresult GetIconHandleFromURLBlocking(nsIMozIconURI* aUrl,
+                                             HICON* aIcon) {
+  nsAutoCString stockIcon;
+  aUrl->GetStockIcon(stockIcon);
+  if (!stockIcon.IsEmpty()) {
+    return GetStockHIcon(aUrl, aIcon);
+  }
+
+  IconPathInfo iconPathInfo;
+  nsresult rv = ExtractIconPathInfoFromUrl(aUrl, &iconPathInfo);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIRunnable> task = NS_NewRunnableFunction(
+      "GetIconHandleFromURLBlocking",
+      [&] { rv = GetIconHandleFromPathInfo(iconPathInfo, aIcon); });
+
+  RefPtr<nsIEventTarget> target = DecodePool::Singleton()->GetIOEventTarget();
+
+  nsresult dispatchResult = SyncRunnable::DispatchToThread(target, task);
+  NS_ENSURE_SUCCESS(dispatchResult, dispatchResult);
+
+  return rv;
+}
+
+static RefPtr<HIconPromise> GetIconHandleFromURLAsync(nsIMozIconURI* aUrl) {
+  RefPtr<HIconPromise::Private> promise = new HIconPromise::Private(__func__);
+
+  nsAutoCString stockIcon;
+  aUrl->GetStockIcon(stockIcon);
+  if (!stockIcon.IsEmpty()) {
+    HICON hIcon = nullptr;
+    nsresult rv = GetStockHIcon(aUrl, &hIcon);
+    if (NS_SUCCEEDED(rv)) {
+      promise->Resolve(hIcon, __func__);
+    } else {
+      promise->Reject(rv, __func__);
+    }
+    return promise;
+  }
+
+  IconPathInfo iconPathInfo;
+  nsresult rv = ExtractIconPathInfoFromUrl(aUrl, &iconPathInfo);
+  if (NS_FAILED(rv)) {
+    promise->Reject(rv, __func__);
+    return promise;
+  }
+
+  nsCOMPtr<nsIRunnable> task = NS_NewRunnableFunction(
+      "GetIconHandleFromURLAsync", [iconPathInfo, promise] {
+        HICON hIcon = nullptr;
+        nsresult rv = GetIconHandleFromPathInfo(iconPathInfo, &hIcon);
+        if (NS_SUCCEEDED(rv)) {
+          promise->Resolve(hIcon, __func__);
+        } else {
+          promise->Reject(rv, __func__);
+        }
+      });
+
+  RefPtr<nsIEventTarget> target = DecodePool::Singleton()->GetIOEventTarget();
+
+  rv = target->Dispatch(task.forget(), NS_DISPATCH_NORMAL);
+  if (NS_FAILED(rv)) {
+    promise->Reject(rv, __func__);
+  }
+
+  return promise;
+}
+
+static RefPtr<nsIconChannel::ByteBufPromise> GetIconBufferFromURLAsync(
+    nsIMozIconURI* aUrl) {
+  RefPtr<nsIconChannel::ByteBufPromise::Private> promise =
+      new nsIconChannel::ByteBufPromise::Private(__func__);
+
+  GetIconHandleFromURLAsync(aUrl)->Then(
+      GetCurrentSerialEventTarget(), __func__,
+      [promise](HICON aIcon) {
+        ByteBuf iconBuffer;
+        nsresult rv = MakeIconBuffer(aIcon, &iconBuffer);
+        if (NS_SUCCEEDED(rv)) {
+          promise->Resolve(std::move(iconBuffer), __func__);
+        } else {
+          promise->Reject(rv, __func__);
+        }
+      },
+      [promise](nsresult rv) { promise->Reject(rv, __func__); });
+
+  return promise;
+}
+
+static nsresult WriteByteBufToOutputStream(const ByteBuf& aBuffer,
+                                           nsIAsyncOutputStream* aStream) {
+  uint32_t written = 0;
+  nsresult rv = aStream->Write(reinterpret_cast<const char*>(aBuffer.mData),
+                               aBuffer.mLen, &written);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return (written == aBuffer.mLen) ? NS_OK : NS_ERROR_UNEXPECTED;
+}
+
+NS_IMPL_ISUPPORTS(nsIconChannel, nsIChannel, nsIRequest, nsIRequestObserver,
+                  nsIStreamListener)
+
+// nsIconChannel methods
+nsIconChannel::nsIconChannel() {}
+
+nsIconChannel::~nsIconChannel() {
+  if (mLoadInfo) {
+    NS_ReleaseOnMainThread("nsIconChannel::mLoadInfo", mLoadInfo.forget());
+  }
+  if (mLoadGroup) {
+    NS_ReleaseOnMainThread("nsIconChannel::mLoadGroup", mLoadGroup.forget());
+  }
+}
+
+nsresult nsIconChannel::Init(nsIURI* uri) {
+  NS_ASSERTION(uri, "no uri");
+  mUrl = uri;
+  mOriginalURI = uri;
+  nsresult rv;
+  mPump = do_CreateInstance(NS_INPUTSTREAMPUMP_CONTRACTID, &rv);
+  return rv;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIRequest methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetName(nsACString& result) { return mUrl->GetSpec(result); }
+
+NS_IMETHODIMP
+nsIconChannel::IsPending(bool* result) { return mPump->IsPending(result); }
+
+NS_IMETHODIMP
+nsIconChannel::GetStatus(nsresult* status) { return mPump->GetStatus(status); }
+
+NS_IMETHODIMP nsIconChannel::SetCanceledReason(const nsACString& aReason) {
+  return SetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsIconChannel::GetCanceledReason(nsACString& aReason) {
+  return GetCanceledReasonImpl(aReason);
+}
+
+NS_IMETHODIMP nsIconChannel::CancelWithReason(nsresult aStatus,
+                                              const nsACString& aReason) {
+  return CancelWithReasonImpl(aStatus, aReason);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Cancel(nsresult status) {
+  mCanceled = true;
+  return mPump->Cancel(status);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetCanceled(bool* result) {
+  *result = mCanceled;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::Suspend(void) { return mPump->Suspend(); }
+
+NS_IMETHODIMP
+nsIconChannel::Resume(void) { return mPump->Resume(); }
+NS_IMETHODIMP
+nsIconChannel::GetLoadGroup(nsILoadGroup** aLoadGroup) {
+  *aLoadGroup = mLoadGroup;
+  NS_IF_ADDREF(*aLoadGroup);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadGroup(nsILoadGroup* aLoadGroup) {
+  mLoadGroup = aLoadGroup;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadFlags(uint32_t* aLoadAttributes) {
+  return mPump->GetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadFlags(uint32_t aLoadAttributes) {
+  return mPump->SetLoadFlags(aLoadAttributes);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetTRRMode(nsIRequest::TRRMode* aTRRMode) {
+  return GetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetTRRMode(nsIRequest::TRRMode aTRRMode) {
+  return SetTRRModeImpl(aTRRMode);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetIsDocument(bool* aIsDocument) {
+  return NS_GetIsDocumentChannel(this, aIsDocument);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// nsIChannel methods:
+
+NS_IMETHODIMP
+nsIconChannel::GetOriginalURI(nsIURI** aURI) {
+  *aURI = mOriginalURI;
+  NS_ADDREF(*aURI);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOriginalURI(nsIURI* aURI) {
+  NS_ENSURE_ARG_POINTER(aURI);
+  mOriginalURI = aURI;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetURI(nsIURI** aURI) {
+  *aURI = mUrl;
+  NS_IF_ADDREF(*aURI);
+  return NS_OK;
+}
+
+// static
+RefPtr<nsIconChannel::ByteBufPromise> nsIconChannel::GetIconAsync(
+    nsIURI* aURI) {
+  MOZ_ASSERT(XRE_IsParentProcess());
+
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMozIconURI> iconURI(do_QueryInterface(aURI, &rv));
+  if (NS_FAILED(rv)) {
+    return ByteBufPromise::CreateAndReject(rv, __func__);
+  }
+
+  return GetIconBufferFromURLAsync(iconURI);
+}
+
+NS_IMETHODIMP
+nsIconChannel::Open(nsIInputStream** aStream) {
+  nsCOMPtr<nsIStreamListener> listener;
+  nsresult rv =
+      nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  MOZ_ASSERT(
+      mLoadInfo->GetSecurityMode() == 0 ||
+          mLoadInfo->GetInitialSecurityCheckDone() ||
+          (mLoadInfo->GetSecurityMode() ==
+               nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL &&
+           mLoadInfo->GetLoadingPrincipal() &&
+           mLoadInfo->GetLoadingPrincipal()->IsSystemPrincipal()),
+      "security flags in loadInfo but doContentSecurityCheck() not called");
+
+  // Double-check that we are actually an icon URL
+  nsCOMPtr<nsIMozIconURI> iconURI(do_QueryInterface(mUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Get the handle for the given icon URI. This may involve the decode I/O
+  // thread, as we can only call SHGetFileInfo() from that thread
+  //
+  // Since this API is synchronous, this call will not return until the decode
+  // I/O thread returns with the icon handle
+  //
+  // Once we have the handle, we create a Windows ICO buffer with it and
+  // dump the buffer into the output end of the pipe. The input end will
+  // be returned to the caller
+  HICON hIcon = nullptr;
+  rv = GetIconHandleFromURLBlocking(iconURI, &hIcon);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  ByteBuf iconBuffer;
+  rv = MakeIconBuffer(hIcon, &iconBuffer);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Create the asynchronous pipe with a blocking read end
+  nsCOMPtr<nsIAsyncInputStream> inputStream;
+  nsCOMPtr<nsIAsyncOutputStream> outputStream;
+  NS_NewPipe2(getter_AddRefs(inputStream), getter_AddRefs(outputStream),
+              false /*nonBlockingInput*/, false /*nonBlockingOutput*/,
+              iconBuffer.mLen /*segmentSize*/, 1 /*segmentCount*/);
+
+  rv = WriteByteBufToOutputStream(iconBuffer, outputStream);
+
+  if (NS_SUCCEEDED(rv)) {
+    inputStream.forget(aStream);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsIconChannel::AsyncOpen(nsIStreamListener* aListener) {
+  nsCOMPtr<nsIStreamListener> listener = aListener;
+  nsresult rv =
+      nsContentSecurityManager::doContentSecurityCheck(this, listener);
+  if (NS_FAILED(rv)) {
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  MOZ_ASSERT(
+      mLoadInfo->GetSecurityMode() == 0 ||
+          mLoadInfo->GetInitialSecurityCheckDone() ||
+          (mLoadInfo->GetSecurityMode() ==
+               nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL &&
+           mLoadInfo->GetLoadingPrincipal() &&
+           mLoadInfo->GetLoadingPrincipal()->IsSystemPrincipal()),
+      "security flags in loadInfo but doContentSecurityCheck() not called");
+
+  mListener = listener;
+
+  rv = StartAsyncOpen();
+  if (NS_FAILED(rv)) {
+    mListener = nullptr;
+    mCallbacks = nullptr;
+    return rv;
+  }
+
+  // Add ourself to the load group, if available
+  if (mLoadGroup) {
+    mLoadGroup->AddRequest(this, nullptr);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsIconChannel::StartAsyncOpen() {
+  // Double-check that we are actually an icon URL
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIMozIconURI> iconURI(do_QueryInterface(mUrl, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Create the asynchronous pipe with a non-blocking read end
+  nsCOMPtr<nsIAsyncInputStream> inputStream;
+  nsCOMPtr<nsIAsyncOutputStream> outputStream;
+  NS_NewPipe2(getter_AddRefs(inputStream), getter_AddRefs(outputStream),
+              true /*nonBlockingInput*/, false /*nonBlockingOutput*/,
+              0 /*segmentSize*/, UINT32_MAX /*segmentCount*/);
+
+  // If we are in content, we asynchronously request the ICO buffer from
+  // the parent process because the APIs to load icons don't work with
+  // Win32k Lockdown
+  using ContentChild = mozilla::dom::ContentChild;
+  if (auto* contentChild = ContentChild::GetSingleton()) {
+    RefPtr<ContentChild::GetSystemIconPromise> iconPromise =
+        contentChild->SendGetSystemIcon(mUrl);
+    if (!iconPromise) {
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    iconPromise->Then(
+        mozilla::GetCurrentSerialEventTarget(), __func__,
+        [outputStream](
+            mozilla::Tuple<nsresult, mozilla::Maybe<ByteBuf>>&& aArg) {
+          nsresult rv = mozilla::Get<0>(aArg);
+          mozilla::Maybe<ByteBuf> iconBuffer = std::move(mozilla::Get<1>(aArg));
+
+          if (NS_SUCCEEDED(rv)) {
+            MOZ_RELEASE_ASSERT(iconBuffer);
+            rv = WriteByteBufToOutputStream(*iconBuffer, outputStream);
+          }
+
+          outputStream->CloseWithStatus(rv);
+        },
+        [outputStream](mozilla::ipc::ResponseRejectReason) {
+          outputStream->CloseWithStatus(NS_ERROR_FAILURE);
+        });
+  } else {
+    // Get the handle for the given icon URI. This may involve the decode I/O
+    // thread, as we can only call SHGetFileInfo() from that thread
+    //
+    // Once we have the handle, we create a Windows ICO buffer with it and
+    // dump the buffer into the output end of the pipe. The input end will be
+    // pumped to our attached nsIStreamListener
+    GetIconBufferFromURLAsync(iconURI)->Then(
+        GetCurrentSerialEventTarget(), __func__,
+        [outputStream](ByteBuf aIconBuffer) {
+          nsresult rv =
+              WriteByteBufToOutputStream(std::move(aIconBuffer), outputStream);
+          outputStream->CloseWithStatus(rv);
+        },
+        [outputStream](nsresult rv) { outputStream->CloseWithStatus(rv); });
+  }
+
+  // Use the main thread for the pumped events unless the load info
+  // specifies otherwise
+  nsCOMPtr<nsIEventTarget> listenerTarget =
+      nsContentUtils::GetEventTargetByLoadInfo(mLoadInfo,
+                                               mozilla::TaskCategory::Other);
+  if (!listenerTarget) {
+    listenerTarget = do_GetMainThread();
+  }
+
+  rv = mPump->Init(inputStream.get(), 0 /*segmentSize*/, 0 /*segmentCount*/,
+                   false /*closeWhenDone*/, listenerTarget);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return mPump->AsyncRead(this);
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentType(nsACString& aContentType) {
+  aContentType.AssignLiteral(IMAGE_ICO);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentType(const nsACString& aContentType) {
+  // It doesn't make sense to set the content-type on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP nsIconChannel::GetContentCharset(nsACString& aContentCharset) {
+  aContentCharset.Truncate();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentCharset(const nsACString& aContentCharset) {
+  // It doesn't make sense to set the content-charset on this type
+  // of channel...
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDisposition(uint32_t* aContentDisposition) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentDisposition(uint32_t aContentDisposition) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDispositionFilename(
+    nsAString& aContentDispositionFilename) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentDispositionFilename(
+    const nsAString& aContentDispositionFilename) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentDispositionHeader(
+    nsACString& aContentDispositionHeader) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetContentLength(int64_t* aContentLength) {
+  *aContentLength = 0;
+  return NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetContentLength(int64_t aContentLength) {
+  MOZ_ASSERT_UNREACHABLE("nsIconChannel::SetContentLength");
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetOwner(nsISupports** aOwner) {
+  *aOwner = mOwner.get();
+  NS_IF_ADDREF(*aOwner);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetOwner(nsISupports* aOwner) {
+  mOwner = aOwner;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetLoadInfo(nsILoadInfo** aLoadInfo) {
+  NS_IF_ADDREF(*aLoadInfo = mLoadInfo);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetLoadInfo(nsILoadInfo* aLoadInfo) {
+  MOZ_RELEASE_ASSERT(aLoadInfo, "loadinfo can't be null");
+  mLoadInfo = aLoadInfo;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetNotificationCallbacks(
+    nsIInterfaceRequestor** aNotificationCallbacks) {
+  *aNotificationCallbacks = mCallbacks.get();
+  NS_IF_ADDREF(*aNotificationCallbacks);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::SetNotificationCallbacks(
+    nsIInterfaceRequestor* aNotificationCallbacks) {
+  mCallbacks = aNotificationCallbacks;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::GetSecurityInfo(nsITransportSecurityInfo** aSecurityInfo) {
+  *aSecurityInfo = nullptr;
+  return NS_OK;
+}
+
+// nsIRequestObserver methods
+NS_IMETHODIMP nsIconChannel::OnStartRequest(nsIRequest* aRequest) {
+  if (mListener) {
+    return mListener->OnStartRequest(this);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsIconChannel::OnStopRequest(nsIRequest* aRequest, nsresult aStatus) {
+  if (mListener) {
+    mListener->OnStopRequest(this, aStatus);
+    mListener = nullptr;
+  }
+
+  // Remove from load group
+  if (mLoadGroup) {
+    mLoadGroup->RemoveRequest(this, nullptr, aStatus);
+  }
+
+  // Drop notification callbacks to prevent cycles.
+  mCallbacks = nullptr;
+
+  return NS_OK;
+}
+
+// nsIStreamListener methods
+NS_IMETHODIMP
+nsIconChannel::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aStream,
+                               uint64_t aOffset, uint32_t aCount) {
+  if (mListener) {
+    return mListener->OnDataAvailable(this, aStream, aOffset, aCount);
+  }
+  return NS_OK;
+}
diff --git a/image/decoders/icon/win/nsIconChannel.h b/image/decoders/icon/win/nsIconChannel.h
new file mode 100644
index 0000000000..4065be76e3
--- /dev/null
+++ b/image/decoders/icon/win/nsIconChannel.h
@@ -0,0 +1,65 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_encoders_icon_win_nsIconChannel_h
+#define mozilla_image_encoders_icon_win_nsIconChannel_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/MozPromise.h"
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsIChannel.h"
+#include "nsILoadGroup.h"
+#include "nsILoadInfo.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIURI.h"
+#include "nsIInputStreamPump.h"
+#include "nsIStreamListener.h"
+
+namespace mozilla::ipc {
+class ByteBuf;
+}
+
+class nsIconChannel final : public nsIChannel, public nsIStreamListener {
+ public:
+  using ByteBufPromise =
+      mozilla::MozPromise<mozilla::ipc::ByteBuf, nsresult, true>;
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIREQUEST
+  NS_DECL_NSICHANNEL
+  NS_DECL_NSIREQUESTOBSERVER
+  NS_DECL_NSISTREAMLISTENER
+
+  nsIconChannel();
+
+  nsresult Init(nsIURI* uri);
+
+  /// Obtains an icon in Windows ICO format as a ByteBuf instead
+  /// of a channel. For use with IPC.
+  static RefPtr<ByteBufPromise> GetIconAsync(nsIURI* aURI);
+
+ private:
+  ~nsIconChannel();
+
+  nsresult StartAsyncOpen();
+
+  nsCOMPtr<nsIURI> mUrl;
+  nsCOMPtr<nsIURI> mOriginalURI;
+  nsCOMPtr<nsILoadGroup> mLoadGroup;
+  nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
+  nsCOMPtr<nsISupports> mOwner;
+  nsCOMPtr<nsILoadInfo> mLoadInfo;
+
+  nsCOMPtr<nsIInputStreamPump> mPump;
+  nsCOMPtr<nsIStreamListener> mListener;
+
+  bool mCanceled = false;
+};
+
+#endif  // mozilla_image_encoders_icon_win_nsIconChannel_h
diff --git a/image/decoders/moz.build b/image/decoders/moz.build
new file mode 100644
index 0000000000..d7e062f843
--- /dev/null
+++ b/image/decoders/moz.build
@@ -0,0 +1,62 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+toolkit = CONFIG["MOZ_WIDGET_TOOLKIT"]
+
+# The Icon Channel stuff really shouldn't live in decoders/icon, but we'll
+# fix that another time.
+if toolkit == "gtk":
+    DIRS += ["icon/gtk", "icon"]
+
+if CONFIG["OS_ARCH"] == "WINNT":
+    DIRS += ["icon/win", "icon"]
+
+if toolkit == "cocoa":
+    DIRS += ["icon/mac", "icon"]
+elif toolkit == "android":
+    DIRS += ["icon/android", "icon"]
+
+UNIFIED_SOURCES += [
+    "EXIF.cpp",
+    "iccjpeg.c",
+    "nsBMPDecoder.cpp",
+    "nsGIFDecoder2.cpp",
+    "nsICODecoder.cpp",
+    "nsIconDecoder.cpp",
+    "nsJPEGDecoder.cpp",
+    "nsPNGDecoder.cpp",
+    "nsWebPDecoder.cpp",
+]
+
+if CONFIG["MOZ_AV1"]:
+    UNIFIED_SOURCES += [
+        "nsAVIFDecoder.cpp",
+    ]
+
+if CONFIG["MOZ_JXL"]:
+    UNIFIED_SOURCES += [
+        "nsJXLDecoder.cpp",
+    ]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+LOCAL_INCLUDES += [
+    # Access to Skia headers for Downscaler.
+    "/gfx/2d",
+    # Decoders need ImageLib headers.
+    "/image",
+    # for libyuv::ARGBAttenuate and ::ARGBUnattenuate
+    "/media/libyuv/libyuv/include",
+]
+
+LOCAL_INCLUDES += CONFIG["SKIA_INCLUDES"]
+
+FINAL_LIBRARY = "xul"
+
+CXXFLAGS += ["-Werror=switch"]
+
+# Add libFuzzer configuration directives
+include("/tools/fuzzing/libfuzzer-config.mozbuild")
diff --git a/image/decoders/nsAVIFDecoder.cpp b/image/decoders/nsAVIFDecoder.cpp
new file mode 100644
index 0000000000..248ce0a3c8
--- /dev/null
+++ b/image/decoders/nsAVIFDecoder.cpp
@@ -0,0 +1,1798 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h"  // Must appear first
+
+#include "nsAVIFDecoder.h"
+
+#include "aom/aomdx.h"
+
+#include "DAV1DDecoder.h"
+#include "gfxPlatform.h"
+#include "mozilla/gfx/Types.h"
+#include "YCbCrUtils.h"
+#include "libyuv.h"
+
+#include "SurfacePipeFactory.h"
+
+#include "mozilla/Telemetry.h"
+#include "mozilla/TelemetryComms.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+
+namespace image {
+
+using Telemetry::LABELS_AVIF_A1LX;
+using Telemetry::LABELS_AVIF_A1OP;
+using Telemetry::LABELS_AVIF_ALPHA;
+using Telemetry::LABELS_AVIF_AOM_DECODE_ERROR;
+using Telemetry::LABELS_AVIF_BIT_DEPTH;
+using Telemetry::LABELS_AVIF_CICP_CP;
+using Telemetry::LABELS_AVIF_CICP_MC;
+using Telemetry::LABELS_AVIF_CICP_TC;
+using Telemetry::LABELS_AVIF_CLAP;
+using Telemetry::LABELS_AVIF_COLR;
+using Telemetry::LABELS_AVIF_DECODE_RESULT;
+using Telemetry::LABELS_AVIF_DECODER;
+using Telemetry::LABELS_AVIF_GRID;
+using Telemetry::LABELS_AVIF_IPRO;
+using Telemetry::LABELS_AVIF_ISPE;
+using Telemetry::LABELS_AVIF_LSEL;
+using Telemetry::LABELS_AVIF_MAJOR_BRAND;
+using Telemetry::LABELS_AVIF_PASP;
+using Telemetry::LABELS_AVIF_PIXI;
+using Telemetry::LABELS_AVIF_SEQUENCE;
+using Telemetry::LABELS_AVIF_YUV_COLOR_SPACE;
+
+static LazyLogModule sAVIFLog("AVIFDecoder");
+
+static const LABELS_AVIF_BIT_DEPTH gColorDepthLabel[] = {
+    LABELS_AVIF_BIT_DEPTH::color_8, LABELS_AVIF_BIT_DEPTH::color_10,
+    LABELS_AVIF_BIT_DEPTH::color_12, LABELS_AVIF_BIT_DEPTH::color_16};
+
+static const LABELS_AVIF_YUV_COLOR_SPACE gColorSpaceLabel[] = {
+    LABELS_AVIF_YUV_COLOR_SPACE::BT601, LABELS_AVIF_YUV_COLOR_SPACE::BT709,
+    LABELS_AVIF_YUV_COLOR_SPACE::BT2020, LABELS_AVIF_YUV_COLOR_SPACE::identity};
+
+static MaybeIntSize GetImageSize(const Mp4parseAvifImage& image) {
+  // Note this does not take cropping via CleanAperture (clap) into account
+  const struct Mp4parseImageSpatialExtents* ispe = image.spatial_extents;
+
+  if (ispe) {
+    // Decoder::PostSize takes int32_t, but ispe contains uint32_t
+    CheckedInt<int32_t> width = ispe->image_width;
+    CheckedInt<int32_t> height = ispe->image_height;
+
+    if (width.isValid() && height.isValid()) {
+      return Some(IntSize{width.value(), height.value()});
+    }
+  }
+
+  return Nothing();
+}
+
+// Translate the number of bits per channel into a single ColorDepth.
+// Return Nothing if the number of bits per channel is not uniform.
+static Maybe<uint8_t> BitsPerChannelToBitDepth(
+    const Mp4parseByteData& bits_per_channel) {
+  if (bits_per_channel.length == 0) {
+    return Nothing();
+  }
+
+  for (uintptr_t i = 1; i < bits_per_channel.length; ++i) {
+    if (bits_per_channel.data[i] != bits_per_channel.data[0]) {
+      // log mismatch
+      return Nothing();
+    }
+  }
+
+  return Some(bits_per_channel.data[0]);
+}
+
+static void RecordPixiTelemetry(Maybe<uint8_t>& pixiBitDepth,
+                                uint8_t aBitstreamBitDepth,
+                                const char* aItemName) {
+  if (pixiBitDepth.isNothing()) {
+    AccumulateCategorical(LABELS_AVIF_PIXI::absent);
+  } else if (pixiBitDepth == Some(aBitstreamBitDepth)) {
+    AccumulateCategorical(LABELS_AVIF_PIXI::valid);
+  } else {
+    MOZ_ASSERT(pixiBitDepth.isSome());
+    MOZ_LOG(sAVIFLog, LogLevel::Error,
+            ("%s item pixi bit depth (%hhu) doesn't match "
+             "bitstream (%hhu)",
+             aItemName, *pixiBitDepth, aBitstreamBitDepth));
+    AccumulateCategorical(LABELS_AVIF_PIXI::bitstream_mismatch);
+  }
+}
+
+// Translate the MIAF/HEIF-based orientation transforms (imir, irot) into
+// ImageLib's representation. Note that the interpretation of imir was reversed
+// Between HEIF (ISO 23008-12:2017) and ISO/IEC 23008-12:2017/DAmd 2. This is
+// handled by mp4parse. See mp4parse::read_imir for details.
+Orientation GetImageOrientation(const Mp4parseAvifImage& image) {
+  // Per MIAF (ISO/IEC 23000-22:2019) § 7.3.6.7
+  //   These properties, if used, shall be indicated to be applied in the
+  //   following order: clean aperture first, then rotation, then mirror.
+  // The Orientation type does the same order, but opposite rotation direction
+
+  const Mp4parseIrot heifRot = image.image_rotation;
+  const Mp4parseImir* heifMir = image.image_mirror;
+  Angle mozRot;
+  Flip mozFlip;
+
+  if (!heifMir) {  // No mirroring
+    mozFlip = Flip::Unflipped;
+
+    switch (heifRot) {
+      case MP4PARSE_IROT_D0:
+        // ⥠ UPWARDS HARPOON WITH BARB LEFT FROM BAR
+        mozRot = Angle::D0;
+        break;
+      case MP4PARSE_IROT_D90:
+        // ⥞ LEFTWARDS HARPOON WITH BARB DOWN FROM BAR
+        mozRot = Angle::D270;
+        break;
+      case MP4PARSE_IROT_D180:
+        // ⥝ DOWNWARDS HARPOON WITH BARB RIGHT FROM BAR
+        mozRot = Angle::D180;
+        break;
+      case MP4PARSE_IROT_D270:
+        // ⥛  RIGHTWARDS HARPOON WITH BARB UP FROM BAR
+        mozRot = Angle::D90;
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE();
+    }
+  } else {
+    MOZ_ASSERT(heifMir);
+    mozFlip = Flip::Horizontal;
+
+    enum class HeifFlippedOrientation : uint8_t {
+      IROT_D0_IMIR_V = (MP4PARSE_IROT_D0 << 1) | MP4PARSE_IMIR_LEFT_RIGHT,
+      IROT_D0_IMIR_H = (MP4PARSE_IROT_D0 << 1) | MP4PARSE_IMIR_TOP_BOTTOM,
+      IROT_D90_IMIR_V = (MP4PARSE_IROT_D90 << 1) | MP4PARSE_IMIR_LEFT_RIGHT,
+      IROT_D90_IMIR_H = (MP4PARSE_IROT_D90 << 1) | MP4PARSE_IMIR_TOP_BOTTOM,
+      IROT_D180_IMIR_V = (MP4PARSE_IROT_D180 << 1) | MP4PARSE_IMIR_LEFT_RIGHT,
+      IROT_D180_IMIR_H = (MP4PARSE_IROT_D180 << 1) | MP4PARSE_IMIR_TOP_BOTTOM,
+      IROT_D270_IMIR_V = (MP4PARSE_IROT_D270 << 1) | MP4PARSE_IMIR_LEFT_RIGHT,
+      IROT_D270_IMIR_H = (MP4PARSE_IROT_D270 << 1) | MP4PARSE_IMIR_TOP_BOTTOM,
+    };
+
+    HeifFlippedOrientation heifO =
+        HeifFlippedOrientation((heifRot << 1) | *heifMir);
+
+    switch (heifO) {
+      case HeifFlippedOrientation::IROT_D0_IMIR_V:
+      case HeifFlippedOrientation::IROT_D180_IMIR_H:
+        // ⥜ UPWARDS HARPOON WITH BARB RIGHT FROM BAR
+        mozRot = Angle::D0;
+        break;
+      case HeifFlippedOrientation::IROT_D270_IMIR_V:
+      case HeifFlippedOrientation::IROT_D90_IMIR_H:
+        // ⥚ LEFTWARDS HARPOON WITH BARB UP FROM BAR
+        mozRot = Angle::D90;
+        break;
+      case HeifFlippedOrientation::IROT_D180_IMIR_V:
+      case HeifFlippedOrientation::IROT_D0_IMIR_H:
+        // ⥡ DOWNWARDS HARPOON WITH BARB LEFT FROM BAR
+        mozRot = Angle::D180;
+        break;
+      case HeifFlippedOrientation::IROT_D90_IMIR_V:
+      case HeifFlippedOrientation::IROT_D270_IMIR_H:
+        // ⥟ RIGHTWARDS HARPOON WITH BARB DOWN FROM BAR
+        mozRot = Angle::D270;
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE();
+    }
+  }
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("GetImageOrientation: (rot%d, imir(%s)) -> (Angle%d, "
+           "Flip%d)",
+           static_cast<int>(heifRot),
+           heifMir ? (*heifMir == MP4PARSE_IMIR_LEFT_RIGHT ? "left-right"
+                                                           : "top-bottom")
+                   : "none",
+           static_cast<int>(mozRot), static_cast<int>(mozFlip)));
+  return Orientation{mozRot, mozFlip};
+}
+
+class AVIFParser {
+ public:
+  static Mp4parseStatus Create(const Mp4parseIo* aIo,
+                               UniquePtr<AVIFParser>& aParserOut) {
+    MOZ_ASSERT(aIo);
+    MOZ_ASSERT(!aParserOut);
+
+    UniquePtr<AVIFParser> p(new AVIFParser(aIo));
+    Mp4parseStatus status = p->Init();
+
+    if (status == MP4PARSE_STATUS_OK) {
+      MOZ_ASSERT(p->mParser);
+      aParserOut = std::move(p);
+    }
+
+    return status;
+  }
+
+  ~AVIFParser() {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug, ("Destroy AVIFParser=%p", this));
+  }
+
+  Mp4parseAvifImage* GetImage() {
+    MOZ_ASSERT(mParser);
+
+    if (mAvifImage.isNothing()) {
+      mAvifImage.emplace();
+      Mp4parseStatus status =
+          mp4parse_avif_get_image(mParser.get(), mAvifImage.ptr());
+      MOZ_LOG(sAVIFLog, LogLevel::Debug,
+              ("[this=%p] mp4parse_avif_get_image -> %d; primary_item length: "
+               "%zu, alpha_item length: %zu",
+               this, status, mAvifImage->primary_image.coded_data.length,
+               mAvifImage->alpha_image.coded_data.length));
+      if (status != MP4PARSE_STATUS_OK) {
+        mAvifImage.reset();
+        return nullptr;
+      }
+    }
+    return mAvifImage.ptr();
+  }
+
+ private:
+  explicit AVIFParser(const Mp4parseIo* aIo) : mIo(aIo) {
+    MOZ_ASSERT(mIo);
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("Create AVIFParser=%p, image.avif.compliance_strictness: %d", this,
+             StaticPrefs::image_avif_compliance_strictness()));
+  }
+
+  Mp4parseStatus Init() {
+    MOZ_ASSERT(!mParser);
+
+    Mp4parseAvifParser* parser = nullptr;
+    Mp4parseStatus status =
+        mp4parse_avif_new(mIo,
+                          static_cast<enum Mp4parseStrictness>(
+                              StaticPrefs::image_avif_compliance_strictness()),
+                          &parser);
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] mp4parse_avif_new status: %d", this, status));
+    if (status == MP4PARSE_STATUS_OK) {
+      mParser.reset(parser);
+    }
+    return status;
+  }
+
+  struct FreeAvifParser {
+    void operator()(Mp4parseAvifParser* aPtr) { mp4parse_avif_free(aPtr); }
+  };
+
+  const Mp4parseIo* mIo;
+  UniquePtr<Mp4parseAvifParser, FreeAvifParser> mParser;
+  Maybe<Mp4parseAvifImage> mAvifImage;
+};
+
+// CICP values (either from the BMFF container or the AV1 sequence header) are
+// used to create the colorspace transform. CICP::MatrixCoefficients is only
+// stored for the sake of telemetry, since the relevant information for YUV ->
+// RGB conversion is stored in mYUVColorSpace.
+//
+// There are three potential sources of color information for an AVIF:
+// 1. ICC profile via a ColourInformationBox (colr) defined in [ISOBMFF]
+//    § 12.1.5 "Colour information" and [MIAF] § 7.3.6.4 "Colour information
+//    property"
+// 2. NCLX (AKA CICP see [ITU-T H.273]) values in the same ColourInformationBox
+//    which can have an ICC profile or NCLX values, not both).
+// 3. NCLX values in the AV1 bitstream
+//
+// The 'colr' box is optional, but there are always CICP values in the AV1
+// bitstream, so it is possible to have both. Per ISOBMFF § 12.1.5.1
+// > If colour information is supplied in both this box, and also in the
+// > video bitstream, this box takes precedence, and over-rides the
+// > information in the bitstream.
+//
+// If present, the ICC profile takes precedence over CICP values, but only
+// specifies the color space, not the matrix coefficients necessary to convert
+// YCbCr data (as most AVIF are encoded) to RGB. The matrix coefficients are
+// always derived from the CICP values for matrix_coefficients (and potentially
+// colour_primaries, but in that case only the CICP values for colour_primaries
+// will be used, not anything harvested from the ICC profile).
+//
+// If there is no ICC profile, the color space transform will be based on the
+// CICP values either from the 'colr' box, or if absent/unspecified, the
+// decoded AV1 sequence header.
+//
+// For values that are 2 (meaning unspecified) after trying both, the
+// fallback values are:
+// - CP:  1 (BT.709/sRGB)
+// - TC: 13 (sRGB)
+// - MC:  6 (BT.601)
+// - Range: Full
+//
+// Additional details here:
+// <https://github.com/AOMediaCodec/libavif/wiki/CICP#unspecified>. Note
+// that this contradicts the current version of [MIAF] § 7.3.6.4 which
+// specifies MC=1 (BT.709). This is revised in [MIAF DAMD2] and confirmed by
+// <https://github.com/AOMediaCodec/av1-avif/issues/77#issuecomment-676526097>
+//
+// The precedence for applying the various values and defaults in the event
+// no valid values are found are managed by the following functions.
+//
+// References:
+// [ISOBMFF]: ISO/IEC 14496-12:2020 <https://www.iso.org/standard/74428.html>
+// [MIAF]: ISO/IEC 23000-22:2019 <https://www.iso.org/standard/74417.html>
+// [MIAF DAMD2]: ISO/IEC 23000-22:2019/FDAmd 2
+// <https://www.iso.org/standard/81634.html>
+// [ITU-T H.273]: Rec. ITU-T H.273 (12/2016)
+//     <https://www.itu.int/rec/T-REC-H.273-201612-I/en>
+struct AVIFDecodedData : layers::PlanarYCbCrData {
+  CICP::ColourPrimaries mColourPrimaries = CICP::CP_UNSPECIFIED;
+  CICP::TransferCharacteristics mTransferCharacteristics = CICP::TC_UNSPECIFIED;
+  CICP::MatrixCoefficients mMatrixCoefficients = CICP::MC_UNSPECIFIED;
+
+  void SetCicpValues(
+      const Mp4parseNclxColourInformation* aNclx,
+      const CICP::ColourPrimaries aAv1ColourPrimaries,
+      const CICP::TransferCharacteristics aAv1TransferCharacteristics,
+      const CICP::MatrixCoefficients aAv1MatrixCoefficients);
+};
+
+// The gfx::YUVColorSpace value is only used in the conversion from YUV -> RGB.
+// Typically this comes directly from the CICP matrix_coefficients value, but
+// certain values require additionally considering the colour_primaries value.
+// See `gfxUtils::CicpToColorSpace` for details. We return a gfx::YUVColorSpace
+// rather than CICP::MatrixCoefficients, since that's what
+// `gfx::ConvertYCbCrATo[A]RGB` uses. `aBitstreamColorSpaceFunc` abstracts the
+// fact that different decoder libraries require different methods for
+// extracting the CICP values from the AV1 bitstream and we don't want to do
+// that work unnecessarily because in addition to wasted effort, it would make
+// the logging more confusing.
+template <typename F>
+static gfx::YUVColorSpace GetAVIFColorSpace(
+    const Mp4parseNclxColourInformation* aNclx, F&& aBitstreamColorSpaceFunc) {
+  return ToMaybe(aNclx)
+      .map([=](const auto& nclx) {
+        return gfxUtils::CicpToColorSpace(
+            static_cast<CICP::MatrixCoefficients>(nclx.matrix_coefficients),
+            static_cast<CICP::ColourPrimaries>(nclx.colour_primaries),
+            sAVIFLog);
+      })
+      .valueOrFrom(aBitstreamColorSpaceFunc)
+      .valueOr(gfx::YUVColorSpace::BT601);
+}
+
+static gfx::ColorRange GetAVIFColorRange(
+    const Mp4parseNclxColourInformation* aNclx,
+    const gfx::ColorRange av1ColorRange) {
+  return ToMaybe(aNclx)
+      .map([=](const auto& nclx) {
+        return aNclx->full_range_flag ? gfx::ColorRange::FULL
+                                      : gfx::ColorRange::LIMITED;
+      })
+      .valueOr(av1ColorRange);
+}
+
+void AVIFDecodedData::SetCicpValues(
+    const Mp4parseNclxColourInformation* aNclx,
+    const CICP::ColourPrimaries aAv1ColourPrimaries,
+    const CICP::TransferCharacteristics aAv1TransferCharacteristics,
+    const CICP::MatrixCoefficients aAv1MatrixCoefficients) {
+  auto cp = CICP::ColourPrimaries::CP_UNSPECIFIED;
+  auto tc = CICP::TransferCharacteristics::TC_UNSPECIFIED;
+  auto mc = CICP::MatrixCoefficients::MC_UNSPECIFIED;
+
+  if (aNclx) {
+    cp = static_cast<CICP::ColourPrimaries>(aNclx->colour_primaries);
+    tc = static_cast<CICP::TransferCharacteristics>(
+        aNclx->transfer_characteristics);
+    mc = static_cast<CICP::MatrixCoefficients>(aNclx->matrix_coefficients);
+  }
+
+  if (cp == CICP::ColourPrimaries::CP_UNSPECIFIED) {
+    if (aAv1ColourPrimaries != CICP::ColourPrimaries::CP_UNSPECIFIED) {
+      cp = aAv1ColourPrimaries;
+      MOZ_LOG(sAVIFLog, LogLevel::Info,
+              ("Unspecified colour_primaries value specified in colr box, "
+               "using AV1 sequence header (%hhu)",
+               cp));
+    } else {
+      cp = CICP::ColourPrimaries::CP_BT709;
+      MOZ_LOG(sAVIFLog, LogLevel::Warning,
+              ("Unspecified colour_primaries value specified in colr box "
+               "or AV1 sequence header, using fallback value (%hhu)",
+               cp));
+    }
+  } else if (cp != aAv1ColourPrimaries) {
+    MOZ_LOG(sAVIFLog, LogLevel::Warning,
+            ("colour_primaries mismatch: colr box = %hhu, AV1 "
+             "sequence header = %hhu, using colr box",
+             cp, aAv1ColourPrimaries));
+  }
+
+  if (tc == CICP::TransferCharacteristics::TC_UNSPECIFIED) {
+    if (aAv1TransferCharacteristics !=
+        CICP::TransferCharacteristics::TC_UNSPECIFIED) {
+      tc = aAv1TransferCharacteristics;
+      MOZ_LOG(sAVIFLog, LogLevel::Info,
+              ("Unspecified transfer_characteristics value specified in "
+               "colr box, using AV1 sequence header (%hhu)",
+               tc));
+    } else {
+      tc = CICP::TransferCharacteristics::TC_SRGB;
+      MOZ_LOG(sAVIFLog, LogLevel::Warning,
+              ("Unspecified transfer_characteristics value specified in "
+               "colr box or AV1 sequence header, using fallback value (%hhu)",
+               tc));
+    }
+  } else if (tc != aAv1TransferCharacteristics) {
+    MOZ_LOG(sAVIFLog, LogLevel::Warning,
+            ("transfer_characteristics mismatch: colr box = %hhu, "
+             "AV1 sequence header = %hhu, using colr box",
+             tc, aAv1TransferCharacteristics));
+  }
+
+  if (mc == CICP::MatrixCoefficients::MC_UNSPECIFIED) {
+    if (aAv1MatrixCoefficients != CICP::MatrixCoefficients::MC_UNSPECIFIED) {
+      mc = aAv1MatrixCoefficients;
+      MOZ_LOG(sAVIFLog, LogLevel::Info,
+              ("Unspecified matrix_coefficients value specified in "
+               "colr box, using AV1 sequence header (%hhu)",
+               mc));
+    } else {
+      mc = CICP::MatrixCoefficients::MC_BT601;
+      MOZ_LOG(sAVIFLog, LogLevel::Warning,
+              ("Unspecified matrix_coefficients value specified in "
+               "colr box or AV1 sequence header, using fallback value (%hhu)",
+               mc));
+    }
+  } else if (mc != aAv1MatrixCoefficients) {
+    MOZ_LOG(sAVIFLog, LogLevel::Warning,
+            ("matrix_coefficients mismatch: colr box = %hhu, "
+             "AV1 sequence header = %hhu, using colr box",
+             mc, aAv1TransferCharacteristics));
+  }
+
+  mColourPrimaries = cp;
+  mTransferCharacteristics = tc;
+  mMatrixCoefficients = mc;
+}
+
+// An interface to do decode and get the decoded data
+class AVIFDecoderInterface {
+ public:
+  using Dav1dResult = nsAVIFDecoder::Dav1dResult;
+  using NonAOMCodecError = nsAVIFDecoder::NonAOMCodecError;
+  using AOMResult = nsAVIFDecoder::AOMResult;
+  using NonDecoderResult = nsAVIFDecoder::NonDecoderResult;
+  using DecodeResult = nsAVIFDecoder::DecodeResult;
+
+  virtual ~AVIFDecoderInterface() = default;
+
+  // Set the mDecodedData if Decode() succeeds
+  virtual DecodeResult Decode(bool aIsMetadataDecode,
+                              const Mp4parseAvifImage& parsedImg) = 0;
+  // Must be called after Decode() succeeds
+  AVIFDecodedData& GetDecodedData() {
+    MOZ_ASSERT(mDecodedData.isSome());
+    return mDecodedData.ref();
+  }
+
+ protected:
+  explicit AVIFDecoderInterface(UniquePtr<AVIFParser>&& aParser)
+      : mParser(std::move(aParser)) {
+    MOZ_ASSERT(mParser);
+  }
+
+  inline static bool IsDecodeSuccess(const DecodeResult& aResult) {
+    return nsAVIFDecoder::IsDecodeSuccess(aResult);
+  }
+
+  UniquePtr<AVIFParser> mParser;
+
+  // The mDecodedData is valid after Decode() succeeds
+  Maybe<AVIFDecodedData> mDecodedData;
+};
+
+class Dav1dDecoder final : AVIFDecoderInterface {
+ public:
+  ~Dav1dDecoder() {
+    MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("Destroy Dav1dDecoder=%p", this));
+
+    if (mPicture) {
+      dav1d_picture_unref(mPicture.take().ptr());
+    }
+
+    if (mAlphaPlane) {
+      dav1d_picture_unref(mAlphaPlane.take().ptr());
+    }
+
+    if (mContext) {
+      dav1d_close(&mContext);
+      MOZ_ASSERT(!mContext);
+    }
+  }
+
+  static DecodeResult Create(UniquePtr<AVIFParser>&& aParser,
+                             UniquePtr<AVIFDecoderInterface>& aDecoder) {
+    UniquePtr<Dav1dDecoder> d(new Dav1dDecoder(std::move(aParser)));
+    Dav1dResult r = d->Init();
+    if (r == 0) {
+      MOZ_ASSERT(d->mContext);
+      aDecoder.reset(d.release());
+    }
+    return AsVariant(r);
+  }
+
+  DecodeResult Decode(bool aIsMetadataDecode,
+                      const Mp4parseAvifImage& parsedImg) override {
+    MOZ_ASSERT(mParser);
+    MOZ_ASSERT(mContext);
+    MOZ_ASSERT(mPicture.isNothing());
+    MOZ_ASSERT(mDecodedData.isNothing());
+
+    MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("[this=%p] Beginning Decode", this));
+
+    if (!parsedImg.primary_image.coded_data.data ||
+        !parsedImg.primary_image.coded_data.length) {
+      return AsVariant(NonDecoderResult::NoPrimaryItem);
+    }
+
+    mPicture.emplace();
+    Dav1dResult r = GetPicture(parsedImg.primary_image.coded_data,
+                               mPicture.ptr(), aIsMetadataDecode);
+    if (r != 0) {
+      mPicture.reset();
+      return AsVariant(r);
+    }
+
+    if (parsedImg.alpha_image.coded_data.data &&
+        parsedImg.alpha_image.coded_data.length) {
+      mAlphaPlane.emplace();
+      Dav1dResult r = GetPicture(parsedImg.alpha_image.coded_data,
+                                 mAlphaPlane.ptr(), aIsMetadataDecode);
+      if (r != 0) {
+        mAlphaPlane.reset();
+        return AsVariant(r);
+      }
+
+      // Per § 4 of the AVIF spec
+      // https://aomediacodec.github.io/av1-avif/#auxiliary-images: An AV1
+      // Alpha Image Item […] shall be encoded with the same bit depth as the
+      // associated master AV1 Image Item
+      if (mPicture->p.bpc != mAlphaPlane->p.bpc) {
+        return AsVariant(NonDecoderResult::AlphaYColorDepthMismatch);
+      }
+    }
+
+    MOZ_ASSERT_IF(mAlphaPlane.isNothing(), !parsedImg.premultiplied_alpha);
+    mDecodedData.emplace(Dav1dPictureToDecodedData(
+        parsedImg.nclx_colour_information, mPicture.ptr(),
+        mAlphaPlane.ptrOr(nullptr), parsedImg.premultiplied_alpha));
+
+    return AsVariant(r);
+  }
+
+ private:
+  explicit Dav1dDecoder(UniquePtr<AVIFParser>&& aParser)
+      : AVIFDecoderInterface(std::move(aParser)) {
+    MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("Create Dav1dDecoder=%p", this));
+  }
+
+  Dav1dResult Init() {
+    MOZ_ASSERT(!mContext);
+
+    Dav1dSettings settings;
+    dav1d_default_settings(&settings);
+    settings.all_layers = 0;
+    settings.max_frame_delay = 1;
+    // TODO: tune settings a la DAV1DDecoder for AV1 (Bug 1681816)
+
+    return dav1d_open(&mContext, &settings);
+  }
+
+  Dav1dResult GetPicture(const Mp4parseByteData& aBytes, Dav1dPicture* aPicture,
+                         bool aIsMetadataDecode) {
+    MOZ_ASSERT(mContext);
+    MOZ_ASSERT(aPicture);
+
+    Dav1dData dav1dData;
+    Dav1dResult r = dav1d_data_wrap(&dav1dData, aBytes.data, aBytes.length,
+                                    Dav1dFreeCallback_s, nullptr);
+
+    MOZ_LOG(sAVIFLog, r == 0 ? LogLevel::Verbose : LogLevel::Error,
+            ("[this=%p] dav1d_data_wrap(%p, %zu) -> %d", this, dav1dData.data,
+             dav1dData.sz, r));
+
+    if (r != 0) {
+      return r;
+    }
+
+    r = dav1d_send_data(mContext, &dav1dData);
+
+    MOZ_LOG(sAVIFLog, r == 0 ? LogLevel::Debug : LogLevel::Error,
+            ("[this=%p] dav1d_send_data -> %d", this, r));
+
+    if (r != 0) {
+      return r;
+    }
+
+    r = dav1d_get_picture(mContext, aPicture);
+
+    MOZ_LOG(sAVIFLog, r == 0 ? LogLevel::Debug : LogLevel::Error,
+            ("[this=%p] dav1d_get_picture -> %d", this, r));
+
+    // When bug 1682662 is fixed, revise this assert and subsequent condition
+    MOZ_ASSERT(aIsMetadataDecode || r == 0);
+
+    // We already have the AVIF_DECODE_RESULT histogram to record all the
+    // successful calls, so only bother recording what type of errors we see
+    // via events. Unlike AOM, dav1d returns an int, not an enum, so this is
+    // the easiest way to see if we're getting unexpected behavior to
+    // investigate.
+    if (aIsMetadataDecode && r != 0) {
+      // Uncomment once bug 1691156 is fixed
+      // mozilla::Telemetry::SetEventRecordingEnabled("avif"_ns, true);
+
+      mozilla::Telemetry::RecordEvent(
+          mozilla::Telemetry::EventID::Avif_Dav1dGetPicture_ReturnValue,
+          Some(nsPrintfCString("%d", r)), Nothing());
+    }
+
+    return r;
+  }
+
+  // A dummy callback for dav1d_data_wrap
+  static void Dav1dFreeCallback_s(const uint8_t* aBuf, void* aCookie) {
+    // The buf is managed by the mParser inside Dav1dDecoder itself. Do
+    // nothing here.
+  }
+
+  static AVIFDecodedData Dav1dPictureToDecodedData(
+      const Mp4parseNclxColourInformation* aNclx, Dav1dPicture* aPicture,
+      Dav1dPicture* aAlphaPlane, bool aPremultipliedAlpha);
+
+  Dav1dContext* mContext = nullptr;
+
+  // The pictures are allocated once Decode() succeeds and will be deallocated
+  // when Dav1dDecoder is destroyed
+  Maybe<Dav1dPicture> mPicture;
+  Maybe<Dav1dPicture> mAlphaPlane;
+};
+
+class AOMDecoder final : AVIFDecoderInterface {
+ public:
+  ~AOMDecoder() {
+    MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("Destroy AOMDecoder=%p", this));
+
+    if (mContext.isSome()) {
+      aom_codec_err_t r = aom_codec_destroy(mContext.ptr());
+      MOZ_LOG(sAVIFLog, LogLevel::Debug,
+              ("[this=%p] aom_codec_destroy -> %d", this, r));
+    }
+  }
+
+  static DecodeResult Create(UniquePtr<AVIFParser>&& aParser,
+                             UniquePtr<AVIFDecoderInterface>& aDecoder) {
+    UniquePtr<AOMDecoder> d(new AOMDecoder(std::move(aParser)));
+    aom_codec_err_t e = d->Init();
+    if (e == AOM_CODEC_OK) {
+      MOZ_ASSERT(d->mContext);
+      aDecoder.reset(d.release());
+    }
+    return AsVariant(AOMResult(e));
+  }
+
+  DecodeResult Decode(bool aIsMetadataDecode,
+                      const Mp4parseAvifImage& parsedImg) override {
+    MOZ_ASSERT(mParser);
+    MOZ_ASSERT(mContext.isSome());
+    MOZ_ASSERT(mDecodedData.isNothing());
+
+    if (!parsedImg.primary_image.coded_data.data ||
+        !parsedImg.primary_image.coded_data.length) {
+      return AsVariant(NonDecoderResult::NoPrimaryItem);
+    }
+
+    aom_image_t* aomImg = nullptr;
+    DecodeResult r = GetImage(parsedImg.primary_image.coded_data, &aomImg,
+                              aIsMetadataDecode);
+    if (!IsDecodeSuccess(r)) {
+      return r;
+    }
+    MOZ_ASSERT(aomImg);
+
+    // The aomImg will be released in next GetImage call (aom_codec_decode
+    // actually). The GetImage could be called again immediately if parsedImg
+    // contains alpha data. Therefore, we need to copy the image and manage it
+    // by AOMDecoder itself.
+    OwnedAOMImage* clonedImg = OwnedAOMImage::CopyFrom(aomImg, false);
+    if (!clonedImg) {
+      return AsVariant(NonDecoderResult::OutOfMemory);
+    }
+    mOwnedImage.reset(clonedImg);
+
+    if (parsedImg.alpha_image.coded_data.data &&
+        parsedImg.alpha_image.coded_data.length) {
+      aom_image_t* alphaImg = nullptr;
+      DecodeResult r = GetImage(parsedImg.alpha_image.coded_data, &alphaImg,
+                                aIsMetadataDecode);
+      if (!IsDecodeSuccess(r)) {
+        return r;
+      }
+      MOZ_ASSERT(alphaImg);
+
+      OwnedAOMImage* clonedAlphaImg = OwnedAOMImage::CopyFrom(alphaImg, true);
+      if (!clonedAlphaImg) {
+        return AsVariant(NonDecoderResult::OutOfMemory);
+      }
+      mOwnedAlphaPlane.reset(clonedAlphaImg);
+
+      // Per § 4 of the AVIF spec
+      // https://aomediacodec.github.io/av1-avif/#auxiliary-images: An AV1
+      // Alpha Image Item […] shall be encoded with the same bit depth as the
+      // associated master AV1 Image Item
+      MOZ_ASSERT(mOwnedImage->GetImage() && mOwnedAlphaPlane->GetImage());
+      if (mOwnedImage->GetImage()->bit_depth !=
+          mOwnedAlphaPlane->GetImage()->bit_depth) {
+        return AsVariant(NonDecoderResult::AlphaYColorDepthMismatch);
+      }
+    }
+
+    MOZ_ASSERT_IF(!mOwnedAlphaPlane, !parsedImg.premultiplied_alpha);
+    mDecodedData.emplace(AOMImageToToDecodedData(
+        parsedImg.nclx_colour_information, mOwnedImage->GetImage(),
+        mOwnedAlphaPlane ? mOwnedAlphaPlane->GetImage() : nullptr,
+        parsedImg.premultiplied_alpha));
+
+    return r;
+  }
+
+ private:
+  explicit AOMDecoder(UniquePtr<AVIFParser>&& aParser)
+      : AVIFDecoderInterface(std::move(aParser)) {
+    MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("Create AOMDecoder=%p", this));
+  }
+
+  aom_codec_err_t Init() {
+    MOZ_ASSERT(mContext.isNothing());
+
+    aom_codec_iface_t* iface = aom_codec_av1_dx();
+    mContext.emplace();
+    aom_codec_err_t r = aom_codec_dec_init(
+        mContext.ptr(), iface, /* cfg = */ nullptr, /* flags = */ 0);
+
+    MOZ_LOG(sAVIFLog, r == AOM_CODEC_OK ? LogLevel::Verbose : LogLevel::Error,
+            ("[this=%p] aom_codec_dec_init -> %d, name = %s", this, r,
+             mContext->name));
+
+    if (r != AOM_CODEC_OK) {
+      mContext.reset();
+    }
+
+    return r;
+  }
+
+  DecodeResult GetImage(const Mp4parseByteData& aData, aom_image_t** aImage,
+                        bool aIsMetadataDecode) {
+    MOZ_ASSERT(mContext.isSome());
+
+    aom_codec_err_t r =
+        aom_codec_decode(mContext.ptr(), aData.data, aData.length, nullptr);
+
+    MOZ_LOG(sAVIFLog, r == AOM_CODEC_OK ? LogLevel::Verbose : LogLevel::Error,
+            ("[this=%p] aom_codec_decode -> %d", this, r));
+
+    if (aIsMetadataDecode) {
+      switch (r) {
+        case AOM_CODEC_OK:
+          // No need to record any telemetry for the common case
+          break;
+        case AOM_CODEC_ERROR:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::error);
+          break;
+        case AOM_CODEC_MEM_ERROR:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::mem_error);
+          break;
+        case AOM_CODEC_ABI_MISMATCH:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::abi_mismatch);
+          break;
+        case AOM_CODEC_INCAPABLE:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::incapable);
+          break;
+        case AOM_CODEC_UNSUP_BITSTREAM:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::unsup_bitstream);
+          break;
+        case AOM_CODEC_UNSUP_FEATURE:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::unsup_feature);
+          break;
+        case AOM_CODEC_CORRUPT_FRAME:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::corrupt_frame);
+          break;
+        case AOM_CODEC_INVALID_PARAM:
+          AccumulateCategorical(LABELS_AVIF_AOM_DECODE_ERROR::invalid_param);
+          break;
+        default:
+          MOZ_ASSERT_UNREACHABLE(
+              "Unknown aom_codec_err_t value from aom_codec_decode");
+      }
+    }
+
+    if (r != AOM_CODEC_OK) {
+      return AsVariant(AOMResult(r));
+    }
+
+    aom_codec_iter_t iter = nullptr;
+    aom_image_t* img = aom_codec_get_frame(mContext.ptr(), &iter);
+
+    MOZ_LOG(sAVIFLog, img == nullptr ? LogLevel::Error : LogLevel::Verbose,
+            ("[this=%p] aom_codec_get_frame -> %p", this, img));
+
+    if (img == nullptr) {
+      return AsVariant(AOMResult(NonAOMCodecError::NoFrame));
+    }
+
+    const CheckedInt<int> decoded_width = img->d_w;
+    const CheckedInt<int> decoded_height = img->d_h;
+
+    if (!decoded_height.isValid() || !decoded_width.isValid()) {
+      MOZ_LOG(sAVIFLog, LogLevel::Debug,
+              ("[this=%p] image dimensions can't be stored in int: d_w: %u, "
+               "d_h: %u",
+               this, img->d_w, img->d_h));
+      return AsVariant(AOMResult(NonAOMCodecError::SizeOverflow));
+    }
+
+    *aImage = img;
+    return AsVariant(AOMResult(r));
+  }
+
+  class OwnedAOMImage {
+   public:
+    ~OwnedAOMImage() {
+      MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("Destroy OwnedAOMImage=%p", this));
+    };
+
+    static OwnedAOMImage* CopyFrom(aom_image_t* aImage, bool aIsAlpha) {
+      MOZ_ASSERT(aImage);
+      UniquePtr<OwnedAOMImage> img(new OwnedAOMImage());
+      if (!img->CloneFrom(aImage, aIsAlpha)) {
+        return nullptr;
+      }
+      return img.release();
+    }
+
+    aom_image_t* GetImage() { return mImage.isSome() ? mImage.ptr() : nullptr; }
+
+   private:
+    OwnedAOMImage() {
+      MOZ_LOG(sAVIFLog, LogLevel::Verbose, ("Create OwnedAOMImage=%p", this));
+    };
+
+    bool CloneFrom(aom_image_t* aImage, bool aIsAlpha) {
+      MOZ_ASSERT(aImage);
+      MOZ_ASSERT(!mImage);
+      MOZ_ASSERT(!mBuffer);
+
+      uint8_t* srcY = aImage->planes[AOM_PLANE_Y];
+      int yStride = aImage->stride[AOM_PLANE_Y];
+      int yHeight = aom_img_plane_height(aImage, AOM_PLANE_Y);
+      size_t yBufSize = yStride * yHeight;
+
+      // If aImage is alpha plane. The data is located in Y channel.
+      if (aIsAlpha) {
+        mBuffer = MakeUnique<uint8_t[]>(yBufSize);
+        if (!mBuffer) {
+          return false;
+        }
+        uint8_t* destY = mBuffer.get();
+        memcpy(destY, srcY, yBufSize);
+        mImage.emplace(*aImage);
+        mImage->planes[AOM_PLANE_Y] = destY;
+
+        return true;
+      }
+
+      uint8_t* srcCb = aImage->planes[AOM_PLANE_U];
+      int cbStride = aImage->stride[AOM_PLANE_U];
+      int cbHeight = aom_img_plane_height(aImage, AOM_PLANE_U);
+      size_t cbBufSize = cbStride * cbHeight;
+
+      uint8_t* srcCr = aImage->planes[AOM_PLANE_V];
+      int crStride = aImage->stride[AOM_PLANE_V];
+      int crHeight = aom_img_plane_height(aImage, AOM_PLANE_V);
+      size_t crBufSize = crStride * crHeight;
+
+      mBuffer = MakeUnique<uint8_t[]>(yBufSize + cbBufSize + crBufSize);
+      if (!mBuffer) {
+        return false;
+      }
+
+      uint8_t* destY = mBuffer.get();
+      uint8_t* destCb = destY + yBufSize;
+      uint8_t* destCr = destCb + cbBufSize;
+
+      memcpy(destY, srcY, yBufSize);
+      memcpy(destCb, srcCb, cbBufSize);
+      memcpy(destCr, srcCr, crBufSize);
+
+      mImage.emplace(*aImage);
+      mImage->planes[AOM_PLANE_Y] = destY;
+      mImage->planes[AOM_PLANE_U] = destCb;
+      mImage->planes[AOM_PLANE_V] = destCr;
+
+      return true;
+    }
+
+    // The mImage's planes are referenced to mBuffer
+    Maybe<aom_image_t> mImage;
+    UniquePtr<uint8_t[]> mBuffer;
+  };
+
+  static AVIFDecodedData AOMImageToToDecodedData(
+      const Mp4parseNclxColourInformation* aNclx, aom_image_t* aImage,
+      aom_image_t* aAlphaPlane, bool aPremultipliedAlpha);
+
+  Maybe<aom_codec_ctx_t> mContext;
+  UniquePtr<OwnedAOMImage> mOwnedImage;
+  UniquePtr<OwnedAOMImage> mOwnedAlphaPlane;
+};
+
+/* static */
+AVIFDecodedData Dav1dDecoder::Dav1dPictureToDecodedData(
+    const Mp4parseNclxColourInformation* aNclx, Dav1dPicture* aPicture,
+    Dav1dPicture* aAlphaPlane, bool aPremultipliedAlpha) {
+  MOZ_ASSERT(aPicture);
+
+  static_assert(std::is_same<int, decltype(aPicture->p.w)>::value);
+  static_assert(std::is_same<int, decltype(aPicture->p.h)>::value);
+
+  AVIFDecodedData data;
+
+  data.mYChannel = static_cast<uint8_t*>(aPicture->data[0]);
+  data.mYStride = aPicture->stride[0];
+  data.mYSkip = aPicture->stride[0] - aPicture->p.w;
+  data.mCbChannel = static_cast<uint8_t*>(aPicture->data[1]);
+  data.mCrChannel = static_cast<uint8_t*>(aPicture->data[2]);
+  data.mCbCrStride = aPicture->stride[1];
+
+  switch (aPicture->p.layout) {
+    case DAV1D_PIXEL_LAYOUT_I400:  // Monochrome, so no Cb or Cr channels
+      break;
+    case DAV1D_PIXEL_LAYOUT_I420:
+      data.mChromaSubsampling = ChromaSubsampling::HALF_WIDTH_AND_HEIGHT;
+      break;
+    case DAV1D_PIXEL_LAYOUT_I422:
+      data.mChromaSubsampling = ChromaSubsampling::HALF_WIDTH;
+      break;
+    case DAV1D_PIXEL_LAYOUT_I444:
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unknown pixel layout");
+  }
+
+  data.mCbSkip = aPicture->stride[1] - aPicture->p.w;
+  data.mCrSkip = aPicture->stride[1] - aPicture->p.w;
+  data.mPictureRect = IntRect(0, 0, aPicture->p.w, aPicture->p.h);
+  data.mStereoMode = StereoMode::MONO;
+  data.mColorDepth = ColorDepthForBitDepth(aPicture->p.bpc);
+
+  MOZ_ASSERT(aPicture->p.bpc == BitDepthForColorDepth(data.mColorDepth));
+
+  data.mYUVColorSpace = GetAVIFColorSpace(aNclx, [=]() {
+    MOZ_LOG(sAVIFLog, LogLevel::Info,
+            ("YUVColorSpace cannot be determined from colr box, using AV1 "
+             "sequence header"));
+    return DAV1DDecoder::GetColorSpace(*aPicture, sAVIFLog);
+  });
+
+  auto av1ColourPrimaries = CICP::ColourPrimaries::CP_UNSPECIFIED;
+  auto av1TransferCharacteristics =
+      CICP::TransferCharacteristics::TC_UNSPECIFIED;
+  auto av1MatrixCoefficients = CICP::MatrixCoefficients::MC_UNSPECIFIED;
+
+  MOZ_ASSERT(aPicture->seq_hdr);
+  auto& seq_hdr = *aPicture->seq_hdr;
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("seq_hdr.color_description_present: %d",
+           seq_hdr.color_description_present));
+  if (seq_hdr.color_description_present) {
+    av1ColourPrimaries = static_cast<CICP::ColourPrimaries>(seq_hdr.pri);
+    av1TransferCharacteristics =
+        static_cast<CICP::TransferCharacteristics>(seq_hdr.trc);
+    av1MatrixCoefficients = static_cast<CICP::MatrixCoefficients>(seq_hdr.mtrx);
+  }
+
+  data.SetCicpValues(aNclx, av1ColourPrimaries, av1TransferCharacteristics,
+                     av1MatrixCoefficients);
+
+  gfx::ColorRange av1ColorRange =
+      seq_hdr.color_range ? gfx::ColorRange::FULL : gfx::ColorRange::LIMITED;
+  data.mColorRange = GetAVIFColorRange(aNclx, av1ColorRange);
+
+  auto colorPrimaries =
+      gfxUtils::CicpToColorPrimaries(data.mColourPrimaries, sAVIFLog);
+  if (colorPrimaries.isSome()) {
+    data.mColorPrimaries = *colorPrimaries;
+  }
+
+  if (aAlphaPlane) {
+    MOZ_ASSERT(aAlphaPlane->stride[0] == data.mYStride);
+    data.mAlpha.emplace();
+    data.mAlpha->mChannel = static_cast<uint8_t*>(aAlphaPlane->data[0]);
+    data.mAlpha->mSize = gfx::IntSize(aAlphaPlane->p.w, aAlphaPlane->p.h);
+    data.mAlpha->mPremultiplied = aPremultipliedAlpha;
+  }
+
+  return data;
+}
+
+/* static */
+AVIFDecodedData AOMDecoder::AOMImageToToDecodedData(
+    const Mp4parseNclxColourInformation* aNclx, aom_image_t* aImage,
+    aom_image_t* aAlphaPlane, bool aPremultipliedAlpha) {
+  MOZ_ASSERT(aImage);
+  MOZ_ASSERT(aImage->stride[AOM_PLANE_Y] == aImage->stride[AOM_PLANE_ALPHA]);
+  MOZ_ASSERT(aImage->stride[AOM_PLANE_Y] >=
+             aom_img_plane_width(aImage, AOM_PLANE_Y));
+  MOZ_ASSERT(aImage->stride[AOM_PLANE_U] == aImage->stride[AOM_PLANE_V]);
+  MOZ_ASSERT(aImage->stride[AOM_PLANE_U] >=
+             aom_img_plane_width(aImage, AOM_PLANE_U));
+  MOZ_ASSERT(aImage->stride[AOM_PLANE_V] >=
+             aom_img_plane_width(aImage, AOM_PLANE_V));
+  MOZ_ASSERT(aom_img_plane_width(aImage, AOM_PLANE_U) ==
+             aom_img_plane_width(aImage, AOM_PLANE_V));
+  MOZ_ASSERT(aom_img_plane_height(aImage, AOM_PLANE_U) ==
+             aom_img_plane_height(aImage, AOM_PLANE_V));
+
+  AVIFDecodedData data;
+
+  data.mYChannel = aImage->planes[AOM_PLANE_Y];
+  data.mYStride = aImage->stride[AOM_PLANE_Y];
+  data.mYSkip =
+      aImage->stride[AOM_PLANE_Y] - aom_img_plane_width(aImage, AOM_PLANE_Y);
+  data.mCbChannel = aImage->planes[AOM_PLANE_U];
+  data.mCrChannel = aImage->planes[AOM_PLANE_V];
+  data.mCbCrStride = aImage->stride[AOM_PLANE_U];
+  data.mCbSkip =
+      aImage->stride[AOM_PLANE_U] - aom_img_plane_width(aImage, AOM_PLANE_U);
+  data.mCrSkip =
+      aImage->stride[AOM_PLANE_V] - aom_img_plane_width(aImage, AOM_PLANE_V);
+  data.mPictureRect = gfx::IntRect(0, 0, aImage->d_w, aImage->d_h);
+  data.mStereoMode = StereoMode::MONO;
+  data.mColorDepth = ColorDepthForBitDepth(aImage->bit_depth);
+
+  if (aImage->x_chroma_shift == 1 && aImage->y_chroma_shift == 1) {
+    data.mChromaSubsampling = gfx::ChromaSubsampling::HALF_WIDTH_AND_HEIGHT;
+  } else if (aImage->x_chroma_shift == 1 && aImage->y_chroma_shift == 0) {
+    data.mChromaSubsampling = gfx::ChromaSubsampling::HALF_WIDTH;
+  } else if (aImage->x_chroma_shift != 0 || aImage->y_chroma_shift != 0) {
+    MOZ_ASSERT_UNREACHABLE("unexpected chroma shifts");
+  }
+
+  MOZ_ASSERT(aImage->bit_depth == BitDepthForColorDepth(data.mColorDepth));
+
+  auto av1ColourPrimaries = static_cast<CICP::ColourPrimaries>(aImage->cp);
+  auto av1TransferCharacteristics =
+      static_cast<CICP::TransferCharacteristics>(aImage->tc);
+  auto av1MatrixCoefficients =
+      static_cast<CICP::MatrixCoefficients>(aImage->mc);
+
+  data.mYUVColorSpace = GetAVIFColorSpace(aNclx, [=]() {
+    MOZ_LOG(sAVIFLog, LogLevel::Info,
+            ("YUVColorSpace cannot be determined from colr box, using AV1 "
+             "sequence header"));
+    return gfxUtils::CicpToColorSpace(av1MatrixCoefficients, av1ColourPrimaries,
+                                      sAVIFLog);
+  });
+
+  gfx::ColorRange av1ColorRange;
+  if (aImage->range == AOM_CR_STUDIO_RANGE) {
+    av1ColorRange = gfx::ColorRange::LIMITED;
+  } else {
+    MOZ_ASSERT(aImage->range == AOM_CR_FULL_RANGE);
+    av1ColorRange = gfx::ColorRange::FULL;
+  }
+  data.mColorRange = GetAVIFColorRange(aNclx, av1ColorRange);
+
+  data.SetCicpValues(aNclx, av1ColourPrimaries, av1TransferCharacteristics,
+                     av1MatrixCoefficients);
+
+  auto colorPrimaries =
+      gfxUtils::CicpToColorPrimaries(data.mColourPrimaries, sAVIFLog);
+  if (colorPrimaries.isSome()) {
+    data.mColorPrimaries = *colorPrimaries;
+  }
+
+  if (aAlphaPlane) {
+    MOZ_ASSERT(aAlphaPlane->stride[AOM_PLANE_Y] == data.mYStride);
+    data.mAlpha.emplace();
+    data.mAlpha->mChannel = aAlphaPlane->planes[AOM_PLANE_Y];
+    data.mAlpha->mSize = gfx::IntSize(aAlphaPlane->d_w, aAlphaPlane->d_h);
+    data.mAlpha->mPremultiplied = aPremultipliedAlpha;
+  }
+
+  return data;
+}
+
+// Wrapper to allow rust to call our read adaptor.
+intptr_t nsAVIFDecoder::ReadSource(uint8_t* aDestBuf, uintptr_t aDestBufSize,
+                                   void* aUserData) {
+  MOZ_ASSERT(aDestBuf);
+  MOZ_ASSERT(aUserData);
+
+  MOZ_LOG(sAVIFLog, LogLevel::Verbose,
+          ("AVIF ReadSource, aDestBufSize: %zu", aDestBufSize));
+
+  auto* decoder = reinterpret_cast<nsAVIFDecoder*>(aUserData);
+
+  MOZ_ASSERT(decoder->mReadCursor);
+
+  size_t bufferLength = decoder->mBufferedData.end() - decoder->mReadCursor;
+  size_t n_bytes = std::min(aDestBufSize, bufferLength);
+
+  MOZ_LOG(
+      sAVIFLog, LogLevel::Verbose,
+      ("AVIF ReadSource, %zu bytes ready, copying %zu", bufferLength, n_bytes));
+
+  memcpy(aDestBuf, decoder->mReadCursor, n_bytes);
+  decoder->mReadCursor += n_bytes;
+
+  return n_bytes;
+}
+
+nsAVIFDecoder::nsAVIFDecoder(RasterImage* aImage) : Decoder(aImage) {
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] nsAVIFDecoder::nsAVIFDecoder", this));
+}
+
+nsAVIFDecoder::~nsAVIFDecoder() {
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] nsAVIFDecoder::~nsAVIFDecoder", this));
+}
+
+LexerResult nsAVIFDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                    IResumable* aOnResume) {
+  MOZ_LOG(sAVIFLog, LogLevel::Info,
+          ("[this=%p] nsAVIFDecoder::DoDecode start", this));
+
+  DecodeResult result = Decode(aIterator, aOnResume);
+
+  RecordDecodeResultTelemetry(result);
+
+  if (result.is<NonDecoderResult>()) {
+    NonDecoderResult r = result.as<NonDecoderResult>();
+    if (r == NonDecoderResult::NeedMoreData) {
+      return LexerResult(Yield::NEED_MORE_DATA);
+    }
+    return r == NonDecoderResult::MetadataOk
+               ? LexerResult(TerminalState::SUCCESS)
+               : LexerResult(TerminalState::FAILURE);
+  }
+
+  MOZ_ASSERT(result.is<Dav1dResult>() || result.is<AOMResult>() ||
+             result.is<Mp4parseStatus>());
+  // If IsMetadataDecode(), a successful parse should return
+  // NonDecoderResult::MetadataOk or else continue to the decode stage
+  MOZ_ASSERT_IF(result.is<Mp4parseStatus>(),
+                result.as<Mp4parseStatus>() != MP4PARSE_STATUS_OK);
+  auto rv = LexerResult(IsDecodeSuccess(result) ? TerminalState::SUCCESS
+                                                : TerminalState::FAILURE);
+  MOZ_LOG(sAVIFLog, LogLevel::Info,
+          ("[this=%p] nsAVIFDecoder::DoDecode end", this));
+  return rv;
+}
+
+nsAVIFDecoder::DecodeResult nsAVIFDecoder::Decode(
+    SourceBufferIterator& aIterator, IResumable* aOnResume) {
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] nsAVIFDecoder::DoDecode", this));
+
+  // Since the SourceBufferIterator doesn't guarantee a contiguous buffer,
+  // but the current mp4parse-rust implementation requires it, always buffer
+  // locally. This keeps the code simpler at the cost of some performance, but
+  // this implementation is only experimental, so we don't want to spend time
+  // optimizing it prematurely.
+  while (!mReadCursor) {
+    SourceBufferIterator::State state =
+        aIterator.AdvanceOrScheduleResume(SIZE_MAX, aOnResume);
+
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] After advance, iterator state is %d", this, state));
+
+    switch (state) {
+      case SourceBufferIterator::WAITING:
+        return AsVariant(NonDecoderResult::NeedMoreData);
+
+      case SourceBufferIterator::COMPLETE:
+        mReadCursor = mBufferedData.begin();
+        break;
+
+      case SourceBufferIterator::READY: {  // copy new data to buffer
+        MOZ_LOG(sAVIFLog, LogLevel::Debug,
+                ("[this=%p] SourceBufferIterator ready, %zu bytes available",
+                 this, aIterator.Length()));
+
+        bool appendSuccess =
+            mBufferedData.append(aIterator.Data(), aIterator.Length());
+
+        if (!appendSuccess) {
+          MOZ_LOG(sAVIFLog, LogLevel::Error,
+                  ("[this=%p] Failed to append %zu bytes to buffer", this,
+                   aIterator.Length()));
+        }
+
+        break;
+      }
+
+      default:
+        MOZ_ASSERT_UNREACHABLE("unexpected SourceBufferIterator state");
+    }
+  }
+
+  Mp4parseIo io = {nsAVIFDecoder::ReadSource, this};
+  UniquePtr<AVIFParser> parser;
+  Mp4parseStatus create_parser_status = AVIFParser::Create(&io, parser);
+
+  if (!parser) {
+    return AsVariant(create_parser_status);
+  }
+
+  const Mp4parseAvifImage* parsedImagePtr = parser->GetImage();
+  if (!parsedImagePtr) {
+    return AsVariant(NonDecoderResult::NoPrimaryItem);
+  }
+  const Mp4parseAvifImage& parsedImg = *parsedImagePtr;
+
+  if (parsedImg.icc_colour_information.data) {
+    const auto& icc = parsedImg.icc_colour_information;
+    MOZ_LOG(
+        sAVIFLog, LogLevel::Debug,
+        ("[this=%p] colr type ICC: %zu bytes %p", this, icc.length, icc.data));
+  }
+
+  if (IsMetadataDecode()) {
+    // Only record metadata telemetry on the metadata decode call, or else it
+    // would be double-counted
+
+    if (parsedImg.pixel_aspect_ratio) {
+      const uint32_t& h_spacing = parsedImg.pixel_aspect_ratio->h_spacing;
+      const uint32_t& v_spacing = parsedImg.pixel_aspect_ratio->v_spacing;
+
+      if (h_spacing == 0 || v_spacing == 0) {
+        AccumulateCategorical(LABELS_AVIF_PASP::invalid);
+      } else if (h_spacing == v_spacing) {
+        AccumulateCategorical(LABELS_AVIF_PASP::square);
+      } else {
+        AccumulateCategorical(LABELS_AVIF_PASP::nonsquare);
+      }
+    } else {
+      AccumulateCategorical(LABELS_AVIF_PASP::absent);
+    }
+
+    const auto& major_brand = parsedImg.major_brand;
+    if (!memcmp(major_brand, "avif", sizeof(major_brand))) {
+      AccumulateCategorical(LABELS_AVIF_MAJOR_BRAND::avif);
+    } else if (!memcmp(major_brand, "avis", sizeof(major_brand))) {
+      AccumulateCategorical(LABELS_AVIF_MAJOR_BRAND::avis);
+    } else {
+      AccumulateCategorical(LABELS_AVIF_MAJOR_BRAND::other);
+    }
+
+    AccumulateCategorical(parsedImg.has_sequence
+                              ? LABELS_AVIF_SEQUENCE::present
+                              : LABELS_AVIF_SEQUENCE::absent);
+
+#define FEATURE_TELEMETRY(fourcc)                                  \
+  AccumulateCategorical((parsedImg.unsupported_features_bitfield & \
+                         (1 << MP4PARSE_FEATURE_##fourcc))         \
+                            ? LABELS_AVIF_##fourcc::present        \
+                            : LABELS_AVIF_##fourcc::absent)
+    FEATURE_TELEMETRY(A1LX);
+    FEATURE_TELEMETRY(A1OP);
+    FEATURE_TELEMETRY(CLAP);
+    FEATURE_TELEMETRY(GRID);
+    FEATURE_TELEMETRY(IPRO);
+    FEATURE_TELEMETRY(LSEL);
+  }
+
+  if (parsedImg.nclx_colour_information) {
+    const auto& nclx = *parsedImg.nclx_colour_information;
+    MOZ_LOG(
+        sAVIFLog, LogLevel::Debug,
+        ("[this=%p] colr type CICP: cp/tc/mc/full-range %u/%u/%u/%s", this,
+         nclx.colour_primaries, nclx.transfer_characteristics,
+         nclx.matrix_coefficients, nclx.full_range_flag ? "true" : "false"));
+  }
+
+  if (!parsedImg.icc_colour_information.data &&
+      !parsedImg.nclx_colour_information) {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] colr box not present", this));
+  }
+
+  if (parsedImg.alpha_image.coded_data.data) {
+    PostHasTransparency();
+  }
+
+  Orientation orientation = StaticPrefs::image_avif_apply_transforms()
+                                ? GetImageOrientation(parsedImg)
+                                : Orientation{};
+  MaybeIntSize parsedImageSize = GetImageSize(parsedImg);
+  Maybe<uint8_t> primaryBitDepth =
+      BitsPerChannelToBitDepth(parsedImg.primary_image.bits_per_channel);
+  Maybe<uint8_t> alphaBitDepth =
+      BitsPerChannelToBitDepth(parsedImg.alpha_image.bits_per_channel);
+
+  if (parsedImageSize.isSome()) {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] Parser returned image size %d x %d (%d/%d bit)", this,
+             parsedImageSize->width, parsedImageSize->height,
+             primaryBitDepth.valueOr(0), alphaBitDepth.valueOr(0)));
+    PostSize(parsedImageSize->width, parsedImageSize->height, orientation);
+    if (IsMetadataDecode()) {
+      MOZ_LOG(
+          sAVIFLog, LogLevel::Debug,
+          ("[this=%p] Finishing metadata decode without image decode", this));
+      return AsVariant(NonDecoderResult::MetadataOk);
+    }
+  } else {
+    MOZ_LOG(sAVIFLog, LogLevel::Error,
+            ("[this=%p] Parser returned no image size, decoding...", this));
+  }
+
+  UniquePtr<AVIFDecoderInterface> decoder;
+  DecodeResult r = StaticPrefs::image_avif_use_dav1d()
+                       ? Dav1dDecoder::Create(std::move(parser), decoder)
+                       : AOMDecoder::Create(std::move(parser), decoder);
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] Create %sDecoder %ssuccessfully", this,
+           StaticPrefs::image_avif_use_dav1d() ? "Dav1d" : "AOM",
+           IsDecodeSuccess(r) ? "" : "un"));
+
+  if (!IsDecodeSuccess(r)) {
+    return r;
+  }
+
+  MOZ_ASSERT(decoder);
+  r = decoder->Decode(IsMetadataDecode(), parsedImg);
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] Decoder%s->Decode() %s", this,
+           StaticPrefs::image_avif_use_dav1d() ? "Dav1d" : "AOM",
+           IsDecodeSuccess(r) ? "succeeds" : "fails"));
+
+  if (!IsDecodeSuccess(r)) {
+    return r;
+  }
+
+  AVIFDecodedData& decodedData = decoder->GetDecodedData();
+
+  MOZ_ASSERT(decodedData.mColourPrimaries !=
+             CICP::ColourPrimaries::CP_UNSPECIFIED);
+  MOZ_ASSERT(decodedData.mTransferCharacteristics !=
+             CICP::TransferCharacteristics::TC_UNSPECIFIED);
+  MOZ_ASSERT(decodedData.mColorRange <= gfx::ColorRange::_Last);
+  MOZ_ASSERT(decodedData.mYUVColorSpace <= gfx::YUVColorSpace::_Last);
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] decodedData.mColorRange: %hhd", this,
+           static_cast<uint8_t>(decodedData.mColorRange)));
+
+  // Technically it's valid but we don't handle it now (Bug 1682318).
+  if (decodedData.mAlpha &&
+      decodedData.mAlpha->mSize != decodedData.YDataSize()) {
+    return AsVariant(NonDecoderResult::AlphaYSizeMismatch);
+  }
+
+  if (parsedImageSize.isNothing()) {
+    MOZ_LOG(sAVIFLog, LogLevel::Error,
+            ("[this=%p] Using decoded image size: %d x %d", this,
+             decodedData.mPictureRect.width, decodedData.mPictureRect.height));
+    PostSize(decodedData.mPictureRect.width, decodedData.mPictureRect.height,
+             orientation);
+    AccumulateCategorical(LABELS_AVIF_ISPE::absent);
+  } else if (decodedData.mPictureRect.width != parsedImageSize->width ||
+             decodedData.mPictureRect.height != parsedImageSize->height) {
+    MOZ_LOG(sAVIFLog, LogLevel::Error,
+            ("[this=%p] Metadata image size doesn't match decoded image size: "
+             "(%d x %d) != (%d x %d)",
+             this, parsedImageSize->width, parsedImageSize->height,
+             decodedData.mPictureRect.width, decodedData.mPictureRect.height));
+    AccumulateCategorical(LABELS_AVIF_ISPE::bitstream_mismatch);
+    return AsVariant(NonDecoderResult::MetadataImageSizeMismatch);
+  } else {
+    AccumulateCategorical(LABELS_AVIF_ISPE::valid);
+  }
+
+  const bool hasAlpha = decodedData.mAlpha.isSome();
+  if (hasAlpha) {
+    PostHasTransparency();
+  }
+
+  if (IsMetadataDecode()) {
+    return AsVariant(NonDecoderResult::MetadataOk);
+  }
+
+  // The following telemetry may depend on the results of decoding.
+  // These data must be recorded after metadata has been decoded
+  // (IsMetadataDecode()=false) or else they would be double-counted.
+
+  AccumulateCategorical(
+      gColorSpaceLabel[static_cast<size_t>(decodedData.mYUVColorSpace)]);
+  AccumulateCategorical(
+      gColorDepthLabel[static_cast<size_t>(decodedData.mColorDepth)]);
+
+  RecordPixiTelemetry(primaryBitDepth,
+                      BitDepthForColorDepth(decodedData.mColorDepth),
+                      "primary");
+
+  if (decodedData.mAlpha) {
+    AccumulateCategorical(LABELS_AVIF_ALPHA::present);
+    RecordPixiTelemetry(alphaBitDepth,
+                        BitDepthForColorDepth(decodedData.mAlpha->mDepth),
+                        "alpha");
+  } else {
+    AccumulateCategorical(LABELS_AVIF_ALPHA::absent);
+  }
+
+  IntSize rgbSize = decodedData.mPictureRect.Size();
+  MOZ_ASSERT(
+      rgbSize ==
+      GetImageMetadata().GetOrientation().ToUnoriented(Size()).ToUnknownSize());
+
+  if (parsedImg.nclx_colour_information &&
+      parsedImg.icc_colour_information.data) {
+    AccumulateCategorical(LABELS_AVIF_COLR::both);
+  } else if (parsedImg.nclx_colour_information) {
+    AccumulateCategorical(LABELS_AVIF_COLR::nclx);
+  } else if (parsedImg.icc_colour_information.data) {
+    AccumulateCategorical(LABELS_AVIF_COLR::icc);
+  } else {
+    AccumulateCategorical(LABELS_AVIF_COLR::absent);
+  }
+
+  if (CICP::IsReserved(decodedData.mColourPrimaries)) {
+    AccumulateCategorical(LABELS_AVIF_CICP_CP::RESERVED_REST);
+  } else {
+    AccumulateCategorical(
+        static_cast<LABELS_AVIF_CICP_CP>(decodedData.mColourPrimaries));
+  }
+
+  if (CICP::IsReserved(decodedData.mTransferCharacteristics)) {
+    AccumulateCategorical(LABELS_AVIF_CICP_TC::RESERVED);
+  } else {
+    AccumulateCategorical(
+        static_cast<LABELS_AVIF_CICP_TC>(decodedData.mTransferCharacteristics));
+  }
+
+  if (CICP::IsReserved(decodedData.mMatrixCoefficients)) {
+    AccumulateCategorical(LABELS_AVIF_CICP_MC::RESERVED);
+  } else {
+    AccumulateCategorical(
+        static_cast<LABELS_AVIF_CICP_MC>(decodedData.mMatrixCoefficients));
+  }
+
+  // Read color profile
+  if (mCMSMode != CMSMode::Off) {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] Processing color profile", this));
+
+    // See comment on AVIFDecodedData
+    if (parsedImg.icc_colour_information.data) {
+      const auto& icc = parsedImg.icc_colour_information;
+      mInProfile = qcms_profile_from_memory(icc.data, icc.length);
+    } else {
+      const auto& cp = decodedData.mColourPrimaries;
+      const auto& tc = decodedData.mTransferCharacteristics;
+
+      if (CICP::IsReserved(cp)) {
+        MOZ_LOG(sAVIFLog, LogLevel::Error,
+                ("[this=%p] colour_primaries reserved value (%hhu) is invalid; "
+                 "failing",
+                 this, cp));
+        return AsVariant(NonDecoderResult::InvalidCICP);
+      }
+
+      if (CICP::IsReserved(tc)) {
+        MOZ_LOG(sAVIFLog, LogLevel::Error,
+                ("[this=%p] transfer_characteristics reserved value (%hhu) is "
+                 "invalid; failing",
+                 this, tc));
+        return AsVariant(NonDecoderResult::InvalidCICP);
+      }
+
+      MOZ_ASSERT(cp != CICP::ColourPrimaries::CP_UNSPECIFIED &&
+                 !CICP::IsReserved(cp));
+      MOZ_ASSERT(tc != CICP::TransferCharacteristics::TC_UNSPECIFIED &&
+                 !CICP::IsReserved(tc));
+
+      mInProfile = qcms_profile_create_cicp(cp, tc);
+    }
+
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] mInProfile %p", this, mInProfile));
+  } else {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] CMSMode::Off, skipping color profile", this));
+  }
+
+  if (mInProfile && GetCMSOutputProfile()) {
+    auto intent = static_cast<qcms_intent>(gfxPlatform::GetRenderingIntent());
+    qcms_data_type inType;
+    qcms_data_type outType;
+
+    // If we're not mandating an intent, use the one from the image.
+    if (gfxPlatform::GetRenderingIntent() == -1) {
+      intent = qcms_profile_get_rendering_intent(mInProfile);
+    }
+
+    uint32_t profileSpace = qcms_profile_get_color_space(mInProfile);
+    if (profileSpace != icSigGrayData) {
+      // If the transform happens with SurfacePipe, it will be in RGBA if we
+      // have an alpha channel, because the swizzle and premultiplication
+      // happens after color management. Otherwise it will be in BGRA because
+      // the swizzle happens at the start.
+      if (hasAlpha) {
+        inType = QCMS_DATA_RGBA_8;
+        outType = QCMS_DATA_RGBA_8;
+      } else {
+        inType = gfxPlatform::GetCMSOSRGBAType();
+        outType = inType;
+      }
+    } else {
+      if (hasAlpha) {
+        inType = QCMS_DATA_GRAYA_8;
+        outType = gfxPlatform::GetCMSOSRGBAType();
+      } else {
+        inType = QCMS_DATA_GRAY_8;
+        outType = gfxPlatform::GetCMSOSRGBAType();
+      }
+    }
+
+    mTransform = qcms_transform_create(mInProfile, inType,
+                                       GetCMSOutputProfile(), outType, intent);
+  }
+
+  // Get suggested format and size. Note that GetYCbCrToRGBDestFormatAndSize
+  // force format to be B8G8R8X8 if it's not.
+  gfx::SurfaceFormat format = SurfaceFormat::OS_RGBX;
+  gfx::GetYCbCrToRGBDestFormatAndSize(decodedData, format, rgbSize);
+  if (hasAlpha) {
+    // We would use libyuv to do the YCbCrA -> ARGB convertion, which only
+    // works for B8G8R8A8.
+    format = SurfaceFormat::B8G8R8A8;
+  }
+
+  const int bytesPerPixel = BytesPerPixel(format);
+
+  const CheckedInt rgbStride = CheckedInt<int>(rgbSize.width) * bytesPerPixel;
+  const CheckedInt rgbBufLength = rgbStride * rgbSize.height;
+
+  if (!rgbStride.isValid() || !rgbBufLength.isValid()) {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] overflow calculating rgbBufLength: rbgSize.width: %d, "
+             "rgbSize.height: %d, "
+             "bytesPerPixel: %u",
+             this, rgbSize.width, rgbSize.height, bytesPerPixel));
+    return AsVariant(NonDecoderResult::SizeOverflow);
+  }
+
+  UniquePtr<uint8_t[]> rgbBuf = MakeUnique<uint8_t[]>(rgbBufLength.value());
+  const uint8_t* endOfRgbBuf = {rgbBuf.get() + rgbBufLength.value()};
+
+  if (!rgbBuf) {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] allocation of %u-byte rgbBuf failed", this,
+             rgbBufLength.value()));
+    return AsVariant(NonDecoderResult::OutOfMemory);
+  }
+
+  if (decodedData.mAlpha) {
+    const auto wantPremultiply =
+        !bool(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA);
+    const bool& hasPremultiply = decodedData.mAlpha->mPremultiplied;
+
+    PremultFunc premultOp = nullptr;
+    if (wantPremultiply && !hasPremultiply) {
+      premultOp = libyuv::ARGBAttenuate;
+    } else if (!wantPremultiply && hasPremultiply) {
+      premultOp = libyuv::ARGBUnattenuate;
+    }
+
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] calling gfx::ConvertYCbCrAToARGB premultOp: %p", this,
+             premultOp));
+    gfx::ConvertYCbCrAToARGB(decodedData, *decodedData.mAlpha, format, rgbSize,
+                             rgbBuf.get(), rgbStride.value(), premultOp);
+  } else {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] calling gfx::ConvertYCbCrToRGB", this));
+    gfx::ConvertYCbCrToRGB(decodedData, format, rgbSize, rgbBuf.get(),
+                           rgbStride.value());
+  }
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] calling SurfacePipeFactory::CreateSurfacePipe", this));
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateReorientSurfacePipe(
+      this, Size(), OutputSize(), format, mTransform, GetOrientation());
+
+  if (!pipe) {
+    MOZ_LOG(sAVIFLog, LogLevel::Debug,
+            ("[this=%p] could not initialize surface pipe", this));
+    return AsVariant(NonDecoderResult::PipeInitError);
+  }
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug, ("[this=%p] writing to surface", this));
+  WriteState writeBufferResult = WriteState::NEED_MORE_DATA;
+  for (uint8_t* rowPtr = rgbBuf.get(); rowPtr < endOfRgbBuf;
+       rowPtr += rgbStride.value()) {
+    writeBufferResult = pipe->WriteBuffer(reinterpret_cast<uint32_t*>(rowPtr));
+
+    Maybe<SurfaceInvalidRect> invalidRect = pipe->TakeInvalidRect();
+    if (invalidRect) {
+      PostInvalidation(invalidRect->mInputSpaceRect,
+                       Some(invalidRect->mOutputSpaceRect));
+    }
+
+    if (writeBufferResult == WriteState::FAILURE) {
+      MOZ_LOG(sAVIFLog, LogLevel::Debug,
+              ("[this=%p] error writing rowPtr to surface pipe", this));
+
+    } else if (writeBufferResult == WriteState::FINISHED) {
+      MOZ_ASSERT(rowPtr + rgbStride.value() == endOfRgbBuf);
+    }
+  }
+
+  MOZ_LOG(sAVIFLog, LogLevel::Debug,
+          ("[this=%p] writing to surface complete", this));
+
+  if (writeBufferResult == WriteState::FINISHED) {
+    PostFrameStop(hasAlpha ? Opacity::SOME_TRANSPARENCY
+                           : Opacity::FULLY_OPAQUE);
+    PostDecodeDone();
+    return r;
+  }
+
+  return AsVariant(NonDecoderResult::WriteBufferError);
+}
+
+/* static */
+bool nsAVIFDecoder::IsDecodeSuccess(const DecodeResult& aResult) {
+  if (aResult.is<Dav1dResult>() || aResult.is<AOMResult>()) {
+    return aResult == DecodeResult(Dav1dResult(0)) ||
+           aResult == DecodeResult(AOMResult(AOM_CODEC_OK));
+  }
+  return false;
+}
+
+void nsAVIFDecoder::RecordDecodeResultTelemetry(
+    const nsAVIFDecoder::DecodeResult& aResult) {
+  if (aResult.is<Mp4parseStatus>()) {
+    switch (aResult.as<Mp4parseStatus>()) {
+      case MP4PARSE_STATUS_OK:
+        MOZ_ASSERT_UNREACHABLE(
+            "Expect NonDecoderResult, Dav1dResult or AOMResult");
+        return;
+      case MP4PARSE_STATUS_BAD_ARG:
+      case MP4PARSE_STATUS_INVALID:
+      case MP4PARSE_STATUS_UNSUPPORTED:
+      case MP4PARSE_STATUS_EOF:
+      case MP4PARSE_STATUS_IO:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::parse_error);
+        return;
+      case MP4PARSE_STATUS_OOM:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::out_of_memory);
+        return;
+      case MP4PARSE_STATUS_MISSING_BRAND:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::missing_brand);
+        return;
+      case MP4PARSE_STATUS_FTYP_NOT_FIRST:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::ftyp_not_first);
+        return;
+      case MP4PARSE_STATUS_NO_IMAGE:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::no_image);
+        return;
+      case MP4PARSE_STATUS_MULTIPLE_MOOV:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::multiple_moov);
+        return;
+      case MP4PARSE_STATUS_NO_MOOV:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::no_moov);
+        return;
+      case MP4PARSE_STATUS_LSEL_NO_ESSENTIAL:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::lsel_no_essential);
+        return;
+      case MP4PARSE_STATUS_A1OP_NO_ESSENTIAL:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::a1op_no_essential);
+        return;
+      case MP4PARSE_STATUS_A1LX_ESSENTIAL:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::a1lx_essential);
+        return;
+      case MP4PARSE_STATUS_TXFORM_NO_ESSENTIAL:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::txform_no_essential);
+        return;
+      case MP4PARSE_STATUS_NO_PRIMARY_ITEM:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::no_primary_item);
+        return;
+      case MP4PARSE_STATUS_IMAGE_ITEM_TYPE:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::image_item_type);
+        return;
+      case MP4PARSE_STATUS_ITEM_TYPE_MISSING:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::item_type_missing);
+        return;
+      case MP4PARSE_STATUS_CONSTRUCTION_METHOD:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::construction_method);
+        return;
+      case MP4PARSE_STATUS_ITEM_LOC_NOT_FOUND:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::item_loc_not_found);
+        return;
+      case MP4PARSE_STATUS_NO_ITEM_DATA_BOX:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::no_item_data_box);
+        return;
+    }
+
+    MOZ_LOG(sAVIFLog, LogLevel::Error,
+            ("[this=%p] unexpected Mp4parseStatus value: %d", this,
+             aResult.as<Mp4parseStatus>()));
+    MOZ_ASSERT(false, "unexpected Mp4parseStatus value");
+    AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::invalid_parse_status);
+
+  } else if (aResult.is<NonDecoderResult>()) {
+    switch (aResult.as<NonDecoderResult>()) {
+      case NonDecoderResult::NeedMoreData:
+        return;
+      case NonDecoderResult::MetadataOk:
+        return;
+      case NonDecoderResult::NoPrimaryItem:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::no_primary_item);
+        return;
+      case NonDecoderResult::SizeOverflow:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::size_overflow);
+        return;
+      case NonDecoderResult::OutOfMemory:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::out_of_memory);
+        return;
+      case NonDecoderResult::PipeInitError:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::pipe_init_error);
+        return;
+      case NonDecoderResult::WriteBufferError:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::write_buffer_error);
+        return;
+      case NonDecoderResult::AlphaYSizeMismatch:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::alpha_y_sz_mismatch);
+        return;
+      case NonDecoderResult::AlphaYColorDepthMismatch:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::alpha_y_bpc_mismatch);
+        return;
+      case NonDecoderResult::MetadataImageSizeMismatch:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::ispe_mismatch);
+        return;
+      case NonDecoderResult::InvalidCICP:
+        AccumulateCategorical(LABELS_AVIF_DECODE_RESULT::invalid_cicp);
+        return;
+    }
+    MOZ_ASSERT_UNREACHABLE("unknown NonDecoderResult");
+  } else {
+    MOZ_ASSERT(aResult.is<Dav1dResult>() || aResult.is<AOMResult>());
+    AccumulateCategorical(aResult.is<Dav1dResult>() ? LABELS_AVIF_DECODER::dav1d
+                                                    : LABELS_AVIF_DECODER::aom);
+    AccumulateCategorical(IsDecodeSuccess(aResult)
+                              ? LABELS_AVIF_DECODE_RESULT::success
+                              : LABELS_AVIF_DECODE_RESULT::decode_error);
+  }
+}
+
+Maybe<Telemetry::HistogramID> nsAVIFDecoder::SpeedHistogram() const {
+  return Some(Telemetry::IMAGE_DECODE_SPEED_AVIF);
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsAVIFDecoder.h b/image/decoders/nsAVIFDecoder.h
new file mode 100644
index 0000000000..c653a8131d
--- /dev/null
+++ b/image/decoders/nsAVIFDecoder.h
@@ -0,0 +1,77 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsAVIFDecoder_h
+#define mozilla_image_decoders_nsAVIFDecoder_h
+
+#include "Decoder.h"
+#include "mp4parse.h"
+#include "SurfacePipe.h"
+
+#include "aom/aom_decoder.h"
+#include "dav1d/dav1d.h"
+
+#include "mozilla/Telemetry.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+class nsAVIFDecoder final : public Decoder {
+ public:
+  virtual ~nsAVIFDecoder();
+
+  DecoderType GetType() const override { return DecoderType::AVIF; }
+
+ protected:
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+  Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
+
+ private:
+  friend class DecoderFactory;
+  friend class AVIFDecoderInterface;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsAVIFDecoder(RasterImage* aImage);
+
+  static intptr_t ReadSource(uint8_t* aDestBuf, uintptr_t aDestBufSize,
+                             void* aUserData);
+
+  typedef int Dav1dResult;
+  enum class NonAOMCodecError { NoFrame, SizeOverflow };
+  typedef Variant<aom_codec_err_t, NonAOMCodecError> AOMResult;
+  enum class NonDecoderResult {
+    NeedMoreData,
+    MetadataOk,
+    NoPrimaryItem,
+    SizeOverflow,
+    OutOfMemory,
+    PipeInitError,
+    WriteBufferError,
+    AlphaYSizeMismatch,
+    AlphaYColorDepthMismatch,
+    MetadataImageSizeMismatch,
+    InvalidCICP,
+  };
+  using DecodeResult =
+      Variant<Mp4parseStatus, NonDecoderResult, Dav1dResult, AOMResult>;
+  DecodeResult Decode(SourceBufferIterator& aIterator, IResumable* aOnResume);
+
+  static bool IsDecodeSuccess(const DecodeResult& aResult);
+
+  void RecordDecodeResultTelemetry(const DecodeResult& aResult);
+
+  Vector<uint8_t> mBufferedData;
+
+  /// Pointer to the next place to read from mBufferedData
+  const uint8_t* mReadCursor = nullptr;
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsAVIFDecoder_h
diff --git a/image/decoders/nsBMPDecoder.cpp b/image/decoders/nsBMPDecoder.cpp
new file mode 100644
index 0000000000..5eea76ea14
--- /dev/null
+++ b/image/decoders/nsBMPDecoder.cpp
@@ -0,0 +1,1271 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This is a cross-platform BMP Decoder, which should work everywhere,
+// including big-endian machines like the PowerPC.
+//
+// BMP is a format that has been extended multiple times. To understand the
+// decoder you need to understand this history. The summary of the history
+// below was determined from the following documents.
+//
+// - http://www.fileformat.info/format/bmp/egff.htm
+// - http://www.fileformat.info/format/os2bmp/egff.htm
+// - http://fileformats.archiveteam.org/wiki/BMP
+// - http://fileformats.archiveteam.org/wiki/OS/2_BMP
+// - https://en.wikipedia.org/wiki/BMP_file_format
+// - https://upload.wikimedia.org/wikipedia/commons/c/c4/BMPfileFormat.png
+//
+// WINDOWS VERSIONS OF THE BMP FORMAT
+// ----------------------------------
+// WinBMPv1.
+// - This version is no longer used and can be ignored.
+//
+// WinBMPv2.
+// - First is a 14 byte file header that includes: the magic number ("BM"),
+//   file size, and offset to the pixel data (|mDataOffset|).
+// - Next is a 12 byte info header which includes: the info header size
+//   (mBIHSize), width, height, number of color planes, and bits-per-pixel
+//   (|mBpp|) which must be 1, 4, 8 or 24.
+// - Next is the semi-optional color table, which has length 2^|mBpp| and has 3
+//   bytes per value (BGR). The color table is required if |mBpp| is 1, 4, or 8.
+// - Next is an optional gap.
+// - Next is the pixel data, which is pointed to by |mDataOffset|.
+//
+// WinBMPv3. This is the most widely used version.
+// - It changed the info header to 40 bytes by taking the WinBMPv2 info
+//   header, enlargening its width and height fields, and adding more fields
+//   including: a compression type (|mCompression|) and number of colors
+//   (|mNumColors|).
+// - The semi-optional color table is now 4 bytes per value (BGR0), and its
+//   length is |mNumColors|, or 2^|mBpp| if |mNumColors| is zero.
+// - |mCompression| can be RGB (i.e. no compression), RLE4 (if |mBpp|==4) or
+//   RLE8 (if |mBpp|==8) values.
+//
+// WinBMPv3-NT. A variant of WinBMPv3.
+// - It did not change the info header layout from WinBMPv3.
+// - |mBpp| can now be 16 or 32, in which case |mCompression| can be RGB or the
+//   new BITFIELDS value; in the latter case an additional 12 bytes of color
+//   bitfields follow the info header.
+//
+// WinBMPv4.
+// - It extended the info header to 108 bytes, including the 12 bytes of color
+//   mask data from WinBMPv3-NT, plus alpha mask data, and also color-space and
+//   gamma correction fields.
+//
+// WinBMPv5.
+// - It extended the info header to 124 bytes, adding color profile data.
+// - It also added an optional color profile table after the pixel data (and
+//   another optional gap).
+//
+// WinBMPv3-ICO. This is a variant of WinBMPv3.
+// - It's the BMP format used for BMP images within ICO files.
+// - The only difference with WinBMPv3 is that if an image is 32bpp and has no
+//   compression, then instead of treating the pixel data as 0RGB it is treated
+//   as ARGB, but only if one or more of the A values are non-zero.
+//
+// Clipboard variants.
+// - It's the BMP format used for BMP images captured from the clipboard.
+// - It is missing the file header, containing the BM signature and the data
+//   offset. Instead the data begins after the header.
+// - If it uses BITFIELDS compression, then there is always an additional 12
+//   bytes of data after the header that must be read. In WinBMPv4+, the masks
+//   are supposed to be included in the header size, which are the values we use
+//   for decoding purposes, but there is additional three masks following the
+//   header which must be skipped to get to the pixel data.
+//
+// OS/2 VERSIONS OF THE BMP FORMAT
+// -------------------------------
+// OS2-BMPv1.
+// - Almost identical to WinBMPv2; the differences are basically ignorable.
+//
+// OS2-BMPv2.
+// - Similar to WinBMPv3.
+// - The info header is 64 bytes but can be reduced to as little as 16; any
+//   omitted fields are treated as zero. The first 40 bytes of these fields are
+//   nearly identical to the WinBMPv3 info header; the remaining 24 bytes are
+//   different.
+// - Also adds compression types "Huffman 1D" and "RLE24", which we don't
+//   support.
+// - We treat OS2-BMPv2 files as if they are WinBMPv3 (i.e. ignore the extra 24
+//   bytes in the info header), which in practice is good enough.
+
+#include "ImageLogging.h"
+#include "nsBMPDecoder.h"
+
+#include <stdlib.h>
+
+#include "mozilla/Attributes.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/Likely.h"
+
+#include "RasterImage.h"
+#include "SurfacePipeFactory.h"
+#include "gfxPlatform.h"
+#include <algorithm>
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace image {
+namespace bmp {
+
+struct Compression {
+  enum { RGB = 0, RLE8 = 1, RLE4 = 2, BITFIELDS = 3 };
+};
+
+// RLE escape codes and constants.
+struct RLE {
+  enum {
+    ESCAPE = 0,
+    ESCAPE_EOL = 0,
+    ESCAPE_EOF = 1,
+    ESCAPE_DELTA = 2,
+
+    SEGMENT_LENGTH = 2,
+    DELTA_LENGTH = 2
+  };
+};
+
+}  // namespace bmp
+
+using namespace bmp;
+
+static double FixedPoint2Dot30_To_Double(uint32_t aFixed) {
+  constexpr double factor = 1.0 / 1073741824.0;  // 2^-30
+  return double(aFixed) * factor;
+}
+
+static float FixedPoint16Dot16_To_Float(uint32_t aFixed) {
+  constexpr double factor = 1.0 / 65536.0;  // 2^-16
+  return double(aFixed) * factor;
+}
+
+static float CalRbgEndpointToQcms(const CalRgbEndpoint& aIn,
+                                  qcms_CIE_xyY& aOut) {
+  aOut.x = FixedPoint2Dot30_To_Double(aIn.mX);
+  aOut.y = FixedPoint2Dot30_To_Double(aIn.mY);
+  aOut.Y = FixedPoint2Dot30_To_Double(aIn.mZ);
+  return FixedPoint16Dot16_To_Float(aIn.mGamma);
+}
+
+static void ReadCalRgbEndpoint(const char* aData, uint32_t aEndpointOffset,
+                               uint32_t aGammaOffset, CalRgbEndpoint& aOut) {
+  aOut.mX = LittleEndian::readUint32(aData + aEndpointOffset);
+  aOut.mY = LittleEndian::readUint32(aData + aEndpointOffset + 4);
+  aOut.mZ = LittleEndian::readUint32(aData + aEndpointOffset + 8);
+  aOut.mGamma = LittleEndian::readUint32(aData + aGammaOffset);
+}
+
+/// Sets the pixel data in aDecoded to the given values.
+/// @param aDecoded pointer to pixel to be set, will be incremented to point to
+/// the next pixel.
+static void SetPixel(uint32_t*& aDecoded, uint8_t aRed, uint8_t aGreen,
+                     uint8_t aBlue, uint8_t aAlpha = 0xFF) {
+  *aDecoded++ = gfxPackedPixelNoPreMultiply(aAlpha, aRed, aGreen, aBlue);
+}
+
+static void SetPixel(uint32_t*& aDecoded, uint8_t idx,
+                     const UniquePtr<ColorTableEntry[]>& aColors) {
+  SetPixel(aDecoded, aColors[idx].mRed, aColors[idx].mGreen,
+           aColors[idx].mBlue);
+}
+
+/// Sets two (or one if aCount = 1) pixels
+/// @param aDecoded where the data is stored. Will be moved 4 resp 8 bytes
+/// depending on whether one or two pixels are written.
+/// @param aData The values for the two pixels
+/// @param aCount Current count. Is decremented by one or two.
+static void Set4BitPixel(uint32_t*& aDecoded, uint8_t aData, uint32_t& aCount,
+                         const UniquePtr<ColorTableEntry[]>& aColors) {
+  uint8_t idx = aData >> 4;
+  SetPixel(aDecoded, idx, aColors);
+  if (--aCount > 0) {
+    idx = aData & 0xF;
+    SetPixel(aDecoded, idx, aColors);
+    --aCount;
+  }
+}
+
+static mozilla::LazyLogModule sBMPLog("BMPDecoder");
+
+// The length of the mBIHSize field in the info header.
+static const uint32_t BIHSIZE_FIELD_LENGTH = 4;
+
+nsBMPDecoder::nsBMPDecoder(RasterImage* aImage, State aState, size_t aLength,
+                           bool aForClipboard)
+    : Decoder(aImage),
+      mLexer(Transition::To(aState, aLength), Transition::TerminateSuccess()),
+      mIsWithinICO(false),
+      mIsForClipboard(aForClipboard),
+      mMayHaveTransparency(false),
+      mDoesHaveTransparency(false),
+      mNumColors(0),
+      mColors(nullptr),
+      mBytesPerColor(0),
+      mPreGapLength(0),
+      mPixelRowSize(0),
+      mCurrentRow(0),
+      mCurrentPos(0),
+      mAbsoluteModeNumPixels(0) {}
+
+// Constructor for normal BMP files or from the clipboard.
+nsBMPDecoder::nsBMPDecoder(RasterImage* aImage, bool aForClipboard)
+    : nsBMPDecoder(aImage,
+                   aForClipboard ? State::INFO_HEADER_SIZE : State::FILE_HEADER,
+                   aForClipboard ? BIHSIZE_FIELD_LENGTH : FILE_HEADER_LENGTH,
+                   aForClipboard) {}
+
+// Constructor used for WinBMPv3-ICO files, which lack a file header.
+nsBMPDecoder::nsBMPDecoder(RasterImage* aImage, uint32_t aDataOffset)
+    : nsBMPDecoder(aImage, State::INFO_HEADER_SIZE, BIHSIZE_FIELD_LENGTH,
+                   /* aForClipboard */ false) {
+  SetIsWithinICO();
+
+  // Even though the file header isn't present in this case, the dataOffset
+  // field is set as if it is, and so we must increment mPreGapLength
+  // accordingly.
+  mPreGapLength += FILE_HEADER_LENGTH;
+
+  // This is the one piece of data we normally get from a BMP file header, so
+  // it must be provided via an argument.
+  mH.mDataOffset = aDataOffset;
+}
+
+nsBMPDecoder::~nsBMPDecoder() {}
+
+// Obtains the size of the compressed image resource.
+int32_t nsBMPDecoder::GetCompressedImageSize() const {
+  // In the RGB case mImageSize might not be set, so compute it manually.
+  MOZ_ASSERT(mPixelRowSize != 0);
+  return mH.mCompression == Compression::RGB ? mPixelRowSize * AbsoluteHeight()
+                                             : mH.mImageSize;
+}
+
+nsresult nsBMPDecoder::BeforeFinishInternal() {
+  if (!IsMetadataDecode() && !mImageData) {
+    return NS_ERROR_FAILURE;  // No image; something went wrong.
+  }
+
+  return NS_OK;
+}
+
+nsresult nsBMPDecoder::FinishInternal() {
+  // We shouldn't be called in error cases.
+  MOZ_ASSERT(!HasError(), "Can't call FinishInternal on error!");
+
+  // We should never make multiple frames.
+  MOZ_ASSERT(GetFrameCount() <= 1, "Multiple BMP frames?");
+
+  // Send notifications if appropriate.
+  if (!IsMetadataDecode() && HasSize()) {
+    // We should have image data.
+    MOZ_ASSERT(mImageData);
+
+    // If it was truncated, fill in the missing pixels as black.
+    while (mCurrentRow > 0) {
+      uint32_t* dst = RowBuffer();
+      while (mCurrentPos < mH.mWidth) {
+        SetPixel(dst, 0, 0, 0);
+        mCurrentPos++;
+      }
+      mCurrentPos = 0;
+      FinishRow();
+    }
+
+    MOZ_ASSERT_IF(mDoesHaveTransparency, mMayHaveTransparency);
+
+    // We have transparency if we either detected some in the image itself
+    // (i.e., |mDoesHaveTransparency| is true) or we're in an ICO, which could
+    // mean we have an AND mask that provides transparency (i.e., |mIsWithinICO|
+    // is true).
+    // XXX(seth): We can tell when we create the decoder if the AND mask is
+    // present, so we could be more precise about this.
+    const Opacity opacity = mDoesHaveTransparency || mIsWithinICO
+                                ? Opacity::SOME_TRANSPARENCY
+                                : Opacity::FULLY_OPAQUE;
+
+    PostFrameStop(opacity);
+    PostDecodeDone();
+  }
+
+  return NS_OK;
+}
+
+// ----------------------------------------
+// Actual Data Processing
+// ----------------------------------------
+
+void BitFields::Value::Set(uint32_t aMask) {
+  mMask = aMask;
+
+  // Handle this exceptional case first. The chosen values don't matter
+  // (because a mask of zero will always give a value of zero) except that
+  // mBitWidth:
+  // - shouldn't be zero, because that would cause an infinite loop in Get();
+  // - shouldn't be 5 or 8, because that could cause a false positive match in
+  //   IsR5G5B5() or IsR8G8B8().
+  if (mMask == 0x0) {
+    mRightShift = 0;
+    mBitWidth = 1;
+    return;
+  }
+
+  // Find the rightmost 1.
+  uint8_t i;
+  for (i = 0; i < 32; i++) {
+    if (mMask & (1 << i)) {
+      break;
+    }
+  }
+  mRightShift = i;
+
+  // Now find the leftmost 1 in the same run of 1s. (If there are multiple runs
+  // of 1s -- which isn't valid -- we'll behave as if only the lowest run was
+  // present, which seems reasonable.)
+  for (i = i + 1; i < 32; i++) {
+    if (!(mMask & (1 << i))) {
+      break;
+    }
+  }
+  mBitWidth = i - mRightShift;
+}
+
+MOZ_ALWAYS_INLINE uint8_t BitFields::Value::Get(uint32_t aValue) const {
+  // Extract the unscaled value.
+  uint32_t v = (aValue & mMask) >> mRightShift;
+
+  // Idea: to upscale v precisely we need to duplicate its bits, possibly
+  // repeatedly, possibly partially in the last case, from bit 7 down to bit 0
+  // in v2. For example:
+  //
+  // - mBitWidth=1:  v2 = v<<7 | v<<6 | ... | v<<1 | v>>0     k -> kkkkkkkk
+  // - mBitWidth=2:  v2 = v<<6 | v<<4 | v<<2 | v>>0          jk -> jkjkjkjk
+  // - mBitWidth=3:  v2 = v<<5 | v<<2 | v>>1                ijk -> ijkijkij
+  // - mBitWidth=4:  v2 = v<<4 | v>>0                      hijk -> hijkhijk
+  // - mBitWidth=5:  v2 = v<<3 | v>>2                     ghijk -> ghijkghi
+  // - mBitWidth=6:  v2 = v<<2 | v>>4                    fghijk -> fghijkfg
+  // - mBitWidth=7:  v2 = v<<1 | v>>6                   efghijk -> efghijke
+  // - mBitWidth=8:  v2 = v>>0                         defghijk -> defghijk
+  // - mBitWidth=9:  v2 = v>>1                        cdefghijk -> cdefghij
+  // - mBitWidth=10: v2 = v>>2                       bcdefghijk -> bcdefghi
+  // - mBitWidth=11: v2 = v>>3                      abcdefghijk -> abcdefgh
+  // - etc.
+  //
+  uint8_t v2 = 0;
+  int32_t i;  // must be a signed integer
+  for (i = 8 - mBitWidth; i > 0; i -= mBitWidth) {
+    v2 |= v << uint32_t(i);
+  }
+  v2 |= v >> uint32_t(-i);
+  return v2;
+}
+
+MOZ_ALWAYS_INLINE uint8_t BitFields::Value::GetAlpha(uint32_t aValue,
+                                                     bool& aHasAlphaOut) const {
+  if (mMask == 0x0) {
+    return 0xff;
+  }
+  aHasAlphaOut = true;
+  return Get(aValue);
+}
+
+MOZ_ALWAYS_INLINE uint8_t BitFields::Value::Get5(uint32_t aValue) const {
+  MOZ_ASSERT(mBitWidth == 5);
+  uint32_t v = (aValue & mMask) >> mRightShift;
+  return (v << 3u) | (v >> 2u);
+}
+
+MOZ_ALWAYS_INLINE uint8_t BitFields::Value::Get8(uint32_t aValue) const {
+  MOZ_ASSERT(mBitWidth == 8);
+  uint32_t v = (aValue & mMask) >> mRightShift;
+  return v;
+}
+
+void BitFields::SetR5G5B5() {
+  mRed.Set(0x7c00);
+  mGreen.Set(0x03e0);
+  mBlue.Set(0x001f);
+}
+
+void BitFields::SetR8G8B8() {
+  mRed.Set(0xff0000);
+  mGreen.Set(0xff00);
+  mBlue.Set(0x00ff);
+}
+
+bool BitFields::IsR5G5B5() const {
+  return mRed.mBitWidth == 5 && mGreen.mBitWidth == 5 && mBlue.mBitWidth == 5 &&
+         mAlpha.mMask == 0x0;
+}
+
+bool BitFields::IsR8G8B8() const {
+  return mRed.mBitWidth == 8 && mGreen.mBitWidth == 8 && mBlue.mBitWidth == 8 &&
+         mAlpha.mMask == 0x0;
+}
+
+uint32_t* nsBMPDecoder::RowBuffer() { return mRowBuffer.get() + mCurrentPos; }
+
+void nsBMPDecoder::ClearRowBufferRemainder() {
+  int32_t len = mH.mWidth - mCurrentPos;
+  memset(RowBuffer(), mMayHaveTransparency ? 0 : 0xFF, len * sizeof(uint32_t));
+}
+
+void nsBMPDecoder::FinishRow() {
+  mPipe.WriteBuffer(mRowBuffer.get());
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (invalidRect) {
+    PostInvalidation(invalidRect->mInputSpaceRect,
+                     Some(invalidRect->mOutputSpaceRect));
+  }
+  mCurrentRow--;
+}
+
+LexerResult nsBMPDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                   IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(
+      aIterator, aOnResume,
+      [=](State aState, const char* aData, size_t aLength) {
+        switch (aState) {
+          case State::FILE_HEADER:
+            return ReadFileHeader(aData, aLength);
+          case State::INFO_HEADER_SIZE:
+            return ReadInfoHeaderSize(aData, aLength);
+          case State::INFO_HEADER_REST:
+            return ReadInfoHeaderRest(aData, aLength);
+          case State::BITFIELDS:
+            return ReadBitfields(aData, aLength);
+          case State::SKIP_TO_COLOR_PROFILE:
+            return Transition::ContinueUnbuffered(State::SKIP_TO_COLOR_PROFILE);
+          case State::FOUND_COLOR_PROFILE:
+            return Transition::To(State::COLOR_PROFILE,
+                                  mH.mColorSpace.mProfile.mLength);
+          case State::COLOR_PROFILE:
+            return ReadColorProfile(aData, aLength);
+          case State::ALLOCATE_SURFACE:
+            return AllocateSurface();
+          case State::COLOR_TABLE:
+            return ReadColorTable(aData, aLength);
+          case State::GAP:
+            return SkipGap();
+          case State::AFTER_GAP:
+            return AfterGap();
+          case State::PIXEL_ROW:
+            return ReadPixelRow(aData);
+          case State::RLE_SEGMENT:
+            return ReadRLESegment(aData);
+          case State::RLE_DELTA:
+            return ReadRLEDelta(aData);
+          case State::RLE_ABSOLUTE:
+            return ReadRLEAbsolute(aData, aLength);
+          default:
+            MOZ_CRASH("Unknown State");
+        }
+      });
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadFileHeader(
+    const char* aData, size_t aLength) {
+  mPreGapLength += aLength;
+
+  bool signatureOk = aData[0] == 'B' && aData[1] == 'M';
+  if (!signatureOk) {
+    return Transition::TerminateFailure();
+  }
+
+  // We ignore the filesize (aData + 2) and reserved (aData + 6) fields.
+
+  mH.mDataOffset = LittleEndian::readUint32(aData + 10);
+
+  return Transition::To(State::INFO_HEADER_SIZE, BIHSIZE_FIELD_LENGTH);
+}
+
+// We read the info header in two steps: (a) read the mBIHSize field to
+// determine how long the header is; (b) read the rest of the header.
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadInfoHeaderSize(
+    const char* aData, size_t aLength) {
+  mH.mBIHSize = LittleEndian::readUint32(aData);
+
+  // Data offset can be wrong so fix it using the BIH size.
+  if (!mIsForClipboard && mH.mDataOffset < mPreGapLength + mH.mBIHSize) {
+    mH.mDataOffset = mPreGapLength + mH.mBIHSize;
+  }
+
+  mPreGapLength += aLength;
+
+  bool bihSizeOk = mH.mBIHSize == InfoHeaderLength::WIN_V2 ||
+                   mH.mBIHSize == InfoHeaderLength::WIN_V3 ||
+                   mH.mBIHSize == InfoHeaderLength::WIN_V4 ||
+                   mH.mBIHSize == InfoHeaderLength::WIN_V5 ||
+                   (mH.mBIHSize >= InfoHeaderLength::OS2_V2_MIN &&
+                    mH.mBIHSize <= InfoHeaderLength::OS2_V2_MAX);
+  if (!bihSizeOk) {
+    return Transition::TerminateFailure();
+  }
+  // ICO BMPs must have a WinBMPv3 header. nsICODecoder should have already
+  // terminated decoding if this isn't the case.
+  MOZ_ASSERT_IF(mIsWithinICO, mH.mBIHSize == InfoHeaderLength::WIN_V3);
+
+  return Transition::To(State::INFO_HEADER_REST,
+                        mH.mBIHSize - BIHSIZE_FIELD_LENGTH);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadInfoHeaderRest(
+    const char* aData, size_t aLength) {
+  mPreGapLength += aLength;
+
+  // |mWidth| and |mHeight| may be signed (Windows) or unsigned (OS/2). We just
+  // read as unsigned because in practice that's good enough.
+  if (mH.mBIHSize == InfoHeaderLength::WIN_V2) {
+    mH.mWidth = LittleEndian::readUint16(aData + 0);
+    mH.mHeight = LittleEndian::readUint16(aData + 2);
+    // We ignore the planes (aData + 4) field; it should always be 1.
+    mH.mBpp = LittleEndian::readUint16(aData + 6);
+  } else {
+    mH.mWidth = LittleEndian::readUint32(aData + 0);
+    mH.mHeight = LittleEndian::readUint32(aData + 4);
+    // We ignore the planes (aData + 4) field; it should always be 1.
+    mH.mBpp = LittleEndian::readUint16(aData + 10);
+
+    // For OS2-BMPv2 the info header may be as little as 16 bytes, so be
+    // careful for these fields.
+    mH.mCompression = aLength >= 16 ? LittleEndian::readUint32(aData + 12) : 0;
+    mH.mImageSize = aLength >= 20 ? LittleEndian::readUint32(aData + 16) : 0;
+    // We ignore the xppm (aData + 20) and yppm (aData + 24) fields.
+    mH.mNumColors = aLength >= 32 ? LittleEndian::readUint32(aData + 28) : 0;
+    // We ignore the important_colors (aData + 36) field.
+
+    // Read color management properties we may need later.
+    mH.mCsType =
+        aLength >= 56
+            ? static_cast<InfoColorSpace>(LittleEndian::readUint32(aData + 52))
+            : InfoColorSpace::SRGB;
+    mH.mCsIntent = aLength >= 108 ? static_cast<InfoColorIntent>(
+                                        LittleEndian::readUint32(aData + 104))
+                                  : InfoColorIntent::IMAGES;
+
+    switch (mH.mCsType) {
+      case InfoColorSpace::CALIBRATED_RGB:
+        if (aLength >= 104) {
+          ReadCalRgbEndpoint(aData, 56, 92, mH.mColorSpace.mCalibrated.mRed);
+          ReadCalRgbEndpoint(aData, 68, 96, mH.mColorSpace.mCalibrated.mGreen);
+          ReadCalRgbEndpoint(aData, 80, 100, mH.mColorSpace.mCalibrated.mBlue);
+        } else {
+          mH.mCsType = InfoColorSpace::SRGB;
+        }
+        break;
+      case InfoColorSpace::EMBEDDED:
+        if (aLength >= 116) {
+          mH.mColorSpace.mProfile.mOffset =
+              LittleEndian::readUint32(aData + 108);
+          mH.mColorSpace.mProfile.mLength =
+              LittleEndian::readUint32(aData + 112);
+        } else {
+          mH.mCsType = InfoColorSpace::SRGB;
+        }
+        break;
+      case InfoColorSpace::LINKED:
+      case InfoColorSpace::SRGB:
+      case InfoColorSpace::WIN:
+      default:
+        // Nothing to be done at this time.
+        break;
+    }
+
+    // For WinBMPv4, WinBMPv5 and (possibly) OS2-BMPv2 there are additional
+    // fields in the info header which we ignore, with the possible exception
+    // of the color bitfields (see below).
+  }
+
+  // The height for BMPs embedded inside an ICO includes spaces for the AND
+  // mask even if it is not present, thus we need to adjust for that here.
+  if (mIsWithinICO) {
+    // XXX(seth): Should we really be writing the absolute value from
+    // the BIH below? Seems like this could be problematic for inverted BMPs.
+    mH.mHeight = abs(mH.mHeight) / 2;
+  }
+
+  // Run with MOZ_LOG=BMPDecoder:5 set to see this output.
+  MOZ_LOG(sBMPLog, LogLevel::Debug,
+          ("BMP: bihsize=%u, %d x %d, bpp=%u, compression=%u, colors=%u, "
+           "data-offset=%u\n",
+           mH.mBIHSize, mH.mWidth, mH.mHeight, uint32_t(mH.mBpp),
+           mH.mCompression, mH.mNumColors, mH.mDataOffset));
+
+  // BMPs with negative width are invalid. Also, reject extremely wide images
+  // to keep the math sane. And reject INT_MIN as a height because you can't
+  // get its absolute value (because -INT_MIN is one more than INT_MAX).
+  const int32_t k64KWidth = 0x0000FFFF;
+  bool sizeOk =
+      0 <= mH.mWidth && mH.mWidth <= k64KWidth && mH.mHeight != INT_MIN;
+  if (!sizeOk) {
+    return Transition::TerminateFailure();
+  }
+
+  // Check mBpp and mCompression.
+  bool bppCompressionOk =
+      (mH.mCompression == Compression::RGB &&
+       (mH.mBpp == 1 || mH.mBpp == 4 || mH.mBpp == 8 || mH.mBpp == 16 ||
+        mH.mBpp == 24 || mH.mBpp == 32)) ||
+      (mH.mCompression == Compression::RLE8 && mH.mBpp == 8) ||
+      (mH.mCompression == Compression::RLE4 && mH.mBpp == 4) ||
+      (mH.mCompression == Compression::BITFIELDS &&
+       // For BITFIELDS compression we require an exact match for one of the
+       // WinBMP BIH sizes; this clearly isn't an OS2 BMP.
+       (mH.mBIHSize == InfoHeaderLength::WIN_V3 ||
+        mH.mBIHSize == InfoHeaderLength::WIN_V4 ||
+        mH.mBIHSize == InfoHeaderLength::WIN_V5) &&
+       (mH.mBpp == 16 || mH.mBpp == 32));
+  if (!bppCompressionOk) {
+    return Transition::TerminateFailure();
+  }
+
+  // Initialize our current row to the top of the image.
+  mCurrentRow = AbsoluteHeight();
+
+  // Round it up to the nearest byte count, then pad to 4-byte boundary.
+  // Compute this even for a metadate decode because GetCompressedImageSize()
+  // relies on it.
+  mPixelRowSize = (mH.mBpp * mH.mWidth + 7) / 8;
+  uint32_t surplus = mPixelRowSize % 4;
+  if (surplus != 0) {
+    mPixelRowSize += 4 - surplus;
+  }
+
+  size_t bitFieldsLengthStillToRead = 0;
+  if (mH.mCompression == Compression::BITFIELDS) {
+    // Need to read bitfields.
+    if (mH.mBIHSize >= InfoHeaderLength::WIN_V4) {
+      // Bitfields are present in the info header, so we can read them
+      // immediately.
+      mBitFields.ReadFromHeader(aData + 36, /* aReadAlpha = */ true);
+
+      // If this came from the clipboard, then we know that even if the header
+      // explicitly includes the bitfield masks, we need to add an additional
+      // offset for the start of the RGB data.
+      if (mIsForClipboard) {
+        mH.mDataOffset += BitFields::LENGTH;
+      }
+    } else {
+      // Bitfields are present after the info header, so we will read them in
+      // ReadBitfields().
+      bitFieldsLengthStillToRead = BitFields::LENGTH;
+    }
+  } else if (mH.mBpp == 16) {
+    // No bitfields specified; use the default 5-5-5 values.
+    mBitFields.SetR5G5B5();
+  } else if (mH.mBpp == 32) {
+    // No bitfields specified; use the default 8-8-8 values.
+    mBitFields.SetR8G8B8();
+  }
+
+  return Transition::To(State::BITFIELDS, bitFieldsLengthStillToRead);
+}
+
+void BitFields::ReadFromHeader(const char* aData, bool aReadAlpha) {
+  mRed.Set(LittleEndian::readUint32(aData + 0));
+  mGreen.Set(LittleEndian::readUint32(aData + 4));
+  mBlue.Set(LittleEndian::readUint32(aData + 8));
+  if (aReadAlpha) {
+    mAlpha.Set(LittleEndian::readUint32(aData + 12));
+  }
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadBitfields(
+    const char* aData, size_t aLength) {
+  mPreGapLength += aLength;
+
+  // If aLength is zero there are no bitfields to read, or we already read them
+  // in ReadInfoHeader().
+  if (aLength != 0) {
+    mBitFields.ReadFromHeader(aData, /* aReadAlpha = */ false);
+  }
+
+  // Note that RLE-encoded BMPs might be transparent because the 'delta' mode
+  // can skip pixels and cause implicit transparency.
+  mMayHaveTransparency = mIsWithinICO || mH.mCompression == Compression::RLE8 ||
+                         mH.mCompression == Compression::RLE4 ||
+                         (mH.mCompression == Compression::BITFIELDS &&
+                          mBitFields.mAlpha.IsPresent());
+  if (mMayHaveTransparency) {
+    PostHasTransparency();
+  }
+
+  // Post our size to the superclass.
+  PostSize(mH.mWidth, AbsoluteHeight());
+  if (HasError()) {
+    return Transition::TerminateFailure();
+  }
+
+  // We've now read all the headers. If we're doing a metadata decode, we're
+  // done.
+  if (IsMetadataDecode()) {
+    return Transition::TerminateSuccess();
+  }
+
+  // Set up the color table, if present; it'll be filled in by ReadColorTable().
+  if (mH.mBpp <= 8) {
+    mNumColors = 1 << mH.mBpp;
+    if (0 < mH.mNumColors && mH.mNumColors < mNumColors) {
+      mNumColors = mH.mNumColors;
+    }
+
+    // Always allocate and zero 256 entries, even though mNumColors might be
+    // smaller, because the file might erroneously index past mNumColors.
+    mColors = MakeUnique<ColorTableEntry[]>(256);
+    memset(mColors.get(), 0, 256 * sizeof(ColorTableEntry));
+
+    // OS/2 Bitmaps have no padding byte.
+    mBytesPerColor = (mH.mBIHSize == InfoHeaderLength::WIN_V2) ? 3 : 4;
+  }
+
+  if (mCMSMode != CMSMode::Off) {
+    switch (mH.mCsType) {
+      case InfoColorSpace::EMBEDDED:
+        return SeekColorProfile(aLength);
+      case InfoColorSpace::CALIBRATED_RGB:
+        PrepareCalibratedColorProfile();
+        break;
+      case InfoColorSpace::SRGB:
+      case InfoColorSpace::WIN:
+        MOZ_LOG(sBMPLog, LogLevel::Debug, ("using sRGB color profile\n"));
+        if (mColors) {
+          // We will transform the color table instead of the output pixels.
+          mTransform = GetCMSsRGBTransform(SurfaceFormat::R8G8B8);
+        } else {
+          mTransform = GetCMSsRGBTransform(SurfaceFormat::OS_RGBA);
+        }
+        break;
+      case InfoColorSpace::LINKED:
+      default:
+        // Not supported, no color management.
+        MOZ_LOG(sBMPLog, LogLevel::Debug, ("color space type not provided\n"));
+        break;
+    }
+  }
+
+  return Transition::To(State::ALLOCATE_SURFACE, 0);
+}
+
+void nsBMPDecoder::PrepareCalibratedColorProfile() {
+  // BMP does not define a white point. Use the same as sRGB. This matches what
+  // Chrome does as well.
+  qcms_CIE_xyY white_point = qcms_white_point_sRGB();
+
+  qcms_CIE_xyYTRIPLE primaries;
+  float redGamma =
+      CalRbgEndpointToQcms(mH.mColorSpace.mCalibrated.mRed, primaries.red);
+  float greenGamma =
+      CalRbgEndpointToQcms(mH.mColorSpace.mCalibrated.mGreen, primaries.green);
+  float blueGamma =
+      CalRbgEndpointToQcms(mH.mColorSpace.mCalibrated.mBlue, primaries.blue);
+
+  // Explicitly verify the profile because sometimes the values from the BMP
+  // header are just garbage.
+  mInProfile = qcms_profile_create_rgb_with_gamma_set(
+      white_point, primaries, redGamma, greenGamma, blueGamma);
+  if (mInProfile && qcms_profile_is_bogus(mInProfile)) {
+    // Bad profile, just use sRGB instead. Release the profile here, so that
+    // our destructor doesn't assume we are the owner for the transform.
+    qcms_profile_release(mInProfile);
+    mInProfile = nullptr;
+  }
+
+  if (mInProfile) {
+    MOZ_LOG(sBMPLog, LogLevel::Debug, ("using calibrated RGB color profile\n"));
+    PrepareColorProfileTransform();
+  } else {
+    MOZ_LOG(sBMPLog, LogLevel::Debug,
+            ("failed to create calibrated RGB color profile, using sRGB\n"));
+    if (mColors) {
+      // We will transform the color table instead of the output pixels.
+      mTransform = GetCMSsRGBTransform(SurfaceFormat::R8G8B8);
+    } else {
+      mTransform = GetCMSsRGBTransform(SurfaceFormat::OS_RGBA);
+    }
+  }
+}
+
+void nsBMPDecoder::PrepareColorProfileTransform() {
+  if (!mInProfile || !GetCMSOutputProfile()) {
+    return;
+  }
+
+  qcms_data_type inType;
+  qcms_data_type outType;
+  if (mColors) {
+    // We will transform the color table instead of the output pixels.
+    inType = QCMS_DATA_RGB_8;
+    outType = QCMS_DATA_RGB_8;
+  } else {
+    inType = gfxPlatform::GetCMSOSRGBAType();
+    outType = inType;
+  }
+
+  qcms_intent intent;
+  switch (mH.mCsIntent) {
+    case InfoColorIntent::BUSINESS:
+      intent = QCMS_INTENT_SATURATION;
+      break;
+    case InfoColorIntent::GRAPHICS:
+      intent = QCMS_INTENT_RELATIVE_COLORIMETRIC;
+      break;
+    case InfoColorIntent::ABS_COLORIMETRIC:
+      intent = QCMS_INTENT_ABSOLUTE_COLORIMETRIC;
+      break;
+    case InfoColorIntent::IMAGES:
+    default:
+      intent = QCMS_INTENT_PERCEPTUAL;
+      break;
+  }
+
+  mTransform = qcms_transform_create(mInProfile, inType, GetCMSOutputProfile(),
+                                     outType, intent);
+  if (!mTransform) {
+    MOZ_LOG(sBMPLog, LogLevel::Debug,
+            ("failed to create color profile transform\n"));
+  }
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::SeekColorProfile(
+    size_t aLength) {
+  // The offset needs to be at least after the color table.
+  uint32_t offset = mH.mColorSpace.mProfile.mOffset;
+  if (offset <= mH.mBIHSize + aLength + mNumColors * mBytesPerColor ||
+      mH.mColorSpace.mProfile.mLength == 0) {
+    return Transition::To(State::ALLOCATE_SURFACE, 0);
+  }
+
+  // We have already read the header and bitfields.
+  offset -= mH.mBIHSize + aLength;
+
+  // We need to skip ahead to search for the embedded color profile. We want
+  // to return to this point once we read it.
+  mReturnIterator = mLexer.Clone(*mIterator, SIZE_MAX);
+  if (!mReturnIterator) {
+    return Transition::TerminateFailure();
+  }
+
+  return Transition::ToUnbuffered(State::FOUND_COLOR_PROFILE,
+                                  State::SKIP_TO_COLOR_PROFILE, offset);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadColorProfile(
+    const char* aData, size_t aLength) {
+  mInProfile = qcms_profile_from_memory(aData, aLength);
+  if (mInProfile) {
+    MOZ_LOG(sBMPLog, LogLevel::Debug, ("using embedded color profile\n"));
+    PrepareColorProfileTransform();
+  }
+
+  // Jump back to where we left off.
+  mIterator = std::move(mReturnIterator);
+  return Transition::To(State::ALLOCATE_SURFACE, 0);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::AllocateSurface() {
+  SurfaceFormat format;
+  SurfacePipeFlags pipeFlags = SurfacePipeFlags();
+
+  if (mMayHaveTransparency) {
+    format = SurfaceFormat::OS_RGBA;
+    if (!(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA)) {
+      pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+    }
+  } else {
+    format = SurfaceFormat::OS_RGBX;
+  }
+
+  if (mH.mHeight >= 0) {
+    // BMPs store their rows in reverse order, so we may need to flip.
+    pipeFlags |= SurfacePipeFlags::FLIP_VERTICALLY;
+  }
+
+  mRowBuffer.reset(new (fallible) uint32_t[mH.mWidth]);
+  if (!mRowBuffer) {
+    return Transition::TerminateFailure();
+  }
+
+  // Only give the color transform to the SurfacePipe if we are not transforming
+  // the color table in advance.
+  qcms_transform* transform = mColors ? nullptr : mTransform;
+
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), FullFrame(), format, format, Nothing(),
+      transform, pipeFlags);
+  if (!pipe) {
+    return Transition::TerminateFailure();
+  }
+
+  mPipe = std::move(*pipe);
+  ClearRowBufferRemainder();
+  return Transition::To(State::COLOR_TABLE, mNumColors * mBytesPerColor);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadColorTable(
+    const char* aData, size_t aLength) {
+  MOZ_ASSERT_IF(aLength != 0, mNumColors > 0 && mColors);
+
+  mPreGapLength += aLength;
+
+  for (uint32_t i = 0; i < mNumColors; i++) {
+    // The format is BGR or BGR0.
+    mColors[i].mBlue = uint8_t(aData[0]);
+    mColors[i].mGreen = uint8_t(aData[1]);
+    mColors[i].mRed = uint8_t(aData[2]);
+    aData += mBytesPerColor;
+  }
+
+  // If we have a color table and a transform, we can avoid transforming each
+  // pixel by doing the table in advance. We color manage every entry in the
+  // table, even if it is smaller in case the BMP is malformed and overruns
+  // its stated color range.
+  if (mColors && mTransform) {
+    qcms_transform_data(mTransform, mColors.get(), mColors.get(), 256);
+  }
+
+  // If we are decoding a BMP from the clipboard, we did not know the data
+  // offset in advance. It is just defined as after the header and color table.
+  if (mIsForClipboard) {
+    mH.mDataOffset += mPreGapLength;
+  }
+
+  // We know how many bytes we've read so far (mPreGapLength) and we know the
+  // offset of the pixel data (mH.mDataOffset), so we can determine the length
+  // of the gap (possibly zero) between the color table and the pixel data.
+  //
+  // If the gap is negative the file must be malformed (e.g. mH.mDataOffset
+  // points into the middle of the color palette instead of past the end) and
+  // we give up.
+  if (mPreGapLength > mH.mDataOffset) {
+    return Transition::TerminateFailure();
+  }
+
+  uint32_t gapLength = mH.mDataOffset - mPreGapLength;
+
+  return Transition::ToUnbuffered(State::AFTER_GAP, State::GAP, gapLength);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::SkipGap() {
+  return Transition::ContinueUnbuffered(State::GAP);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::AfterGap() {
+  // If there are no pixels we can stop.
+  //
+  // XXX: normally, if there are no pixels we will have stopped decoding before
+  // now, outside of this decoder. However, if the BMP is within an ICO file,
+  // it's possible that the ICO claimed the image had a non-zero size while the
+  // BMP claims otherwise. This test is to catch that awkward case. If we ever
+  // come up with a more general solution to this ICO-and-BMP-disagree-on-size
+  // problem, this test can be removed.
+  if (mH.mWidth == 0 || mH.mHeight == 0) {
+    return Transition::TerminateSuccess();
+  }
+
+  bool hasRLE = mH.mCompression == Compression::RLE8 ||
+                mH.mCompression == Compression::RLE4;
+  return hasRLE ? Transition::To(State::RLE_SEGMENT, RLE::SEGMENT_LENGTH)
+                : Transition::To(State::PIXEL_ROW, mPixelRowSize);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadPixelRow(
+    const char* aData) {
+  MOZ_ASSERT(mCurrentRow > 0);
+  MOZ_ASSERT(mCurrentPos == 0);
+
+  const uint8_t* src = reinterpret_cast<const uint8_t*>(aData);
+  uint32_t* dst = RowBuffer();
+  uint32_t lpos = mH.mWidth;
+  switch (mH.mBpp) {
+    case 1:
+      while (lpos > 0) {
+        int8_t bit;
+        uint8_t idx;
+        for (bit = 7; bit >= 0 && lpos > 0; bit--) {
+          idx = (*src >> bit) & 1;
+          SetPixel(dst, idx, mColors);
+          --lpos;
+        }
+        ++src;
+      }
+      break;
+
+    case 4:
+      while (lpos > 0) {
+        Set4BitPixel(dst, *src, lpos, mColors);
+        ++src;
+      }
+      break;
+
+    case 8:
+      while (lpos > 0) {
+        SetPixel(dst, *src, mColors);
+        --lpos;
+        ++src;
+      }
+      break;
+
+    case 16:
+      if (mBitFields.IsR5G5B5()) {
+        // Specialize this common case.
+        while (lpos > 0) {
+          uint16_t val = LittleEndian::readUint16(src);
+          SetPixel(dst, mBitFields.mRed.Get5(val), mBitFields.mGreen.Get5(val),
+                   mBitFields.mBlue.Get5(val));
+          --lpos;
+          src += 2;
+        }
+      } else {
+        bool anyHasAlpha = false;
+        while (lpos > 0) {
+          uint16_t val = LittleEndian::readUint16(src);
+          SetPixel(dst, mBitFields.mRed.Get(val), mBitFields.mGreen.Get(val),
+                   mBitFields.mBlue.Get(val),
+                   mBitFields.mAlpha.GetAlpha(val, anyHasAlpha));
+          --lpos;
+          src += 2;
+        }
+        if (anyHasAlpha) {
+          MOZ_ASSERT(mMayHaveTransparency);
+          mDoesHaveTransparency = true;
+        }
+      }
+      break;
+
+    case 24:
+      while (lpos > 0) {
+        SetPixel(dst, src[2], src[1], src[0]);
+        --lpos;
+        src += 3;
+      }
+      break;
+
+    case 32:
+      if (mH.mCompression == Compression::RGB && mIsWithinICO &&
+          mH.mBpp == 32) {
+        // This is a special case only used for 32bpp WinBMPv3-ICO files, which
+        // could be in either 0RGB or ARGB format. We start by assuming it's
+        // an 0RGB image. If we hit a non-zero alpha value, then we know it's
+        // actually an ARGB image, and change tack accordingly.
+        // (Note: a fully-transparent ARGB image is indistinguishable from a
+        // 0RGB image, and we will render such an image as a 0RGB image, i.e.
+        // opaquely. This is unlikely to be a problem in practice.)
+        while (lpos > 0) {
+          if (!mDoesHaveTransparency && src[3] != 0) {
+            // Up until now this looked like an 0RGB image, but we now know
+            // it's actually an ARGB image. Which means every pixel we've seen
+            // so far has been fully transparent. So we go back and redo them.
+
+            // Tell the SurfacePipe to go back to the start.
+            mPipe.ResetToFirstRow();
+
+            // Redo the complete rows we've already done.
+            MOZ_ASSERT(mCurrentPos == 0);
+            int32_t currentRow = mCurrentRow;
+            mCurrentRow = AbsoluteHeight();
+            ClearRowBufferRemainder();
+            while (mCurrentRow > currentRow) {
+              FinishRow();
+            }
+
+            // Reset the row pointer back to where we started.
+            dst = RowBuffer() + (mH.mWidth - lpos);
+
+            MOZ_ASSERT(mMayHaveTransparency);
+            mDoesHaveTransparency = true;
+          }
+
+          // If mDoesHaveTransparency is false, treat this as an 0RGB image.
+          // Otherwise, treat this as an ARGB image.
+          SetPixel(dst, src[2], src[1], src[0],
+                   mDoesHaveTransparency ? src[3] : 0xff);
+          src += 4;
+          --lpos;
+        }
+      } else if (mBitFields.IsR8G8B8()) {
+        // Specialize this common case.
+        while (lpos > 0) {
+          uint32_t val = LittleEndian::readUint32(src);
+          SetPixel(dst, mBitFields.mRed.Get8(val), mBitFields.mGreen.Get8(val),
+                   mBitFields.mBlue.Get8(val));
+          --lpos;
+          src += 4;
+        }
+      } else {
+        bool anyHasAlpha = false;
+        while (lpos > 0) {
+          uint32_t val = LittleEndian::readUint32(src);
+          SetPixel(dst, mBitFields.mRed.Get(val), mBitFields.mGreen.Get(val),
+                   mBitFields.mBlue.Get(val),
+                   mBitFields.mAlpha.GetAlpha(val, anyHasAlpha));
+          --lpos;
+          src += 4;
+        }
+        if (anyHasAlpha) {
+          MOZ_ASSERT(mMayHaveTransparency);
+          mDoesHaveTransparency = true;
+        }
+      }
+      break;
+
+    default:
+      MOZ_CRASH("Unsupported color depth; earlier check didn't catch it?");
+  }
+
+  FinishRow();
+  return mCurrentRow == 0 ? Transition::TerminateSuccess()
+                          : Transition::To(State::PIXEL_ROW, mPixelRowSize);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadRLESegment(
+    const char* aData) {
+  if (mCurrentRow == 0) {
+    return Transition::TerminateSuccess();
+  }
+
+  uint8_t byte1 = uint8_t(aData[0]);
+  uint8_t byte2 = uint8_t(aData[1]);
+
+  if (byte1 != RLE::ESCAPE) {
+    // Encoded mode consists of two bytes: byte1 specifies the number of
+    // consecutive pixels to be drawn using the color index contained in
+    // byte2.
+    //
+    // Work around bitmaps that specify too many pixels.
+    uint32_t pixelsNeeded = std::min<uint32_t>(mH.mWidth - mCurrentPos, byte1);
+    if (pixelsNeeded) {
+      uint32_t* dst = RowBuffer();
+      mCurrentPos += pixelsNeeded;
+      if (mH.mCompression == Compression::RLE8) {
+        do {
+          SetPixel(dst, byte2, mColors);
+          pixelsNeeded--;
+        } while (pixelsNeeded);
+      } else {
+        do {
+          Set4BitPixel(dst, byte2, pixelsNeeded, mColors);
+        } while (pixelsNeeded);
+      }
+    }
+    return Transition::To(State::RLE_SEGMENT, RLE::SEGMENT_LENGTH);
+  }
+
+  if (byte2 == RLE::ESCAPE_EOL) {
+    ClearRowBufferRemainder();
+    mCurrentPos = 0;
+    FinishRow();
+    return mCurrentRow == 0
+               ? Transition::TerminateSuccess()
+               : Transition::To(State::RLE_SEGMENT, RLE::SEGMENT_LENGTH);
+  }
+
+  if (byte2 == RLE::ESCAPE_EOF) {
+    return Transition::TerminateSuccess();
+  }
+
+  if (byte2 == RLE::ESCAPE_DELTA) {
+    return Transition::To(State::RLE_DELTA, RLE::DELTA_LENGTH);
+  }
+
+  // Absolute mode. |byte2| gives the number of pixels. The length depends on
+  // whether it's 4-bit or 8-bit RLE. Also, the length must be even (and zero
+  // padding is used to achieve this when necessary).
+  MOZ_ASSERT(mAbsoluteModeNumPixels == 0);
+  mAbsoluteModeNumPixels = byte2;
+  uint32_t length = byte2;
+  if (mH.mCompression == Compression::RLE4) {
+    length = (length + 1) / 2;  // halve, rounding up
+  }
+  if (length & 1) {
+    length++;
+  }
+  return Transition::To(State::RLE_ABSOLUTE, length);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadRLEDelta(
+    const char* aData) {
+  // Delta encoding makes it possible to skip pixels making part of the image
+  // transparent.
+  MOZ_ASSERT(mMayHaveTransparency);
+  mDoesHaveTransparency = true;
+
+  // Clear the skipped pixels. (This clears to the end of the row,
+  // which is perfect if there's a Y delta and harmless if not).
+  ClearRowBufferRemainder();
+
+  // Handle the XDelta.
+  mCurrentPos += uint8_t(aData[0]);
+  if (mCurrentPos > mH.mWidth) {
+    mCurrentPos = mH.mWidth;
+  }
+
+  // Handle the Y Delta.
+  int32_t yDelta = std::min<int32_t>(uint8_t(aData[1]), mCurrentRow);
+  if (yDelta > 0) {
+    // Commit the current row (the first of the skipped rows).
+    FinishRow();
+
+    // Clear and commit the remaining skipped rows. We want to be careful not
+    // to change mCurrentPos here.
+    memset(mRowBuffer.get(), 0, mH.mWidth * sizeof(uint32_t));
+    for (int32_t line = 1; line < yDelta; line++) {
+      FinishRow();
+    }
+  }
+
+  return mCurrentRow == 0
+             ? Transition::TerminateSuccess()
+             : Transition::To(State::RLE_SEGMENT, RLE::SEGMENT_LENGTH);
+}
+
+LexerTransition<nsBMPDecoder::State> nsBMPDecoder::ReadRLEAbsolute(
+    const char* aData, size_t aLength) {
+  uint32_t n = mAbsoluteModeNumPixels;
+  mAbsoluteModeNumPixels = 0;
+
+  if (mCurrentPos + n > uint32_t(mH.mWidth)) {
+    // Some DIB RLE8 encoders count a padding byte as the absolute mode
+    // pixel number at the end of the row.
+    if (mH.mCompression == Compression::RLE8 && n > 0 && (n & 1) == 0 &&
+        mCurrentPos + n - uint32_t(mH.mWidth) == 1 && aLength > 0 &&
+        aData[aLength - 1] == 0) {
+      n--;
+    } else {
+      // Bad data. Stop decoding; at least part of the image may have been
+      // decoded.
+      return Transition::TerminateSuccess();
+    }
+  }
+
+  // In absolute mode, n represents the number of pixels that follow, each of
+  // which contains the color index of a single pixel.
+  uint32_t* dst = RowBuffer();
+  uint32_t iSrc = 0;
+  uint32_t* oldPos = dst;
+  if (mH.mCompression == Compression::RLE8) {
+    while (n > 0) {
+      SetPixel(dst, aData[iSrc], mColors);
+      n--;
+      iSrc++;
+    }
+  } else {
+    while (n > 0) {
+      Set4BitPixel(dst, aData[iSrc], n, mColors);
+      iSrc++;
+    }
+  }
+  mCurrentPos += dst - oldPos;
+
+  // We should read all the data (unless the last byte is zero padding).
+  MOZ_ASSERT(iSrc == aLength - 1 || iSrc == aLength);
+
+  return Transition::To(State::RLE_SEGMENT, RLE::SEGMENT_LENGTH);
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsBMPDecoder.h b/image/decoders/nsBMPDecoder.h
new file mode 100644
index 0000000000..c7990834b9
--- /dev/null
+++ b/image/decoders/nsBMPDecoder.h
@@ -0,0 +1,285 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsBMPDecoder_h
+#define mozilla_image_decoders_nsBMPDecoder_h
+
+#include "BMPHeaders.h"
+#include "Decoder.h"
+#include "gfxColor.h"
+#include "StreamingLexer.h"
+#include "SurfacePipe.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+namespace image {
+
+namespace bmp {
+
+struct CalRgbEndpoint {
+  uint32_t mGamma;
+  uint32_t mX;
+  uint32_t mY;
+  uint32_t mZ;
+};
+
+/// This struct contains the fields from the file header and info header that
+/// we use during decoding. (Excluding bitfields fields, which are kept in
+/// BitFields.)
+struct Header {
+  uint32_t mDataOffset;       // Offset to raster data.
+  uint32_t mBIHSize;          // Header size.
+  int32_t mWidth;             // Image width.
+  int32_t mHeight;            // Image height.
+  uint16_t mBpp;              // Bits per pixel.
+  uint32_t mCompression;      // See struct Compression for valid values.
+  uint32_t mImageSize;        // (compressed) image size. Can be 0 if
+                              // mCompression==0.
+  uint32_t mNumColors;        // Used colors.
+  InfoColorSpace mCsType;     // Color space type.
+  InfoColorIntent mCsIntent;  // Color space intent.
+
+  union {
+    struct {
+      CalRgbEndpoint mRed;
+      CalRgbEndpoint mGreen;
+      CalRgbEndpoint mBlue;
+    } mCalibrated;
+
+    struct {
+      uint32_t mOffset;
+      uint32_t mLength;
+    } mProfile;
+  } mColorSpace;
+
+  Header()
+      : mDataOffset(0),
+        mBIHSize(0),
+        mWidth(0),
+        mHeight(0),
+        mBpp(0),
+        mCompression(0),
+        mImageSize(0),
+        mNumColors(0),
+        mCsType(InfoColorSpace::SRGB),
+        mCsIntent(InfoColorIntent::IMAGES) {}
+};
+
+/// An entry in the color table.
+struct ColorTableEntry {
+  uint8_t mRed;
+  uint8_t mGreen;
+  uint8_t mBlue;
+};
+
+/// All the color-related bitfields for 16bpp and 32bpp images. We use this
+/// even for older format BMPs that don't have explicit bitfields.
+class BitFields {
+  class Value {
+    friend class BitFields;
+
+    uint32_t mMask;       // The mask for the value.
+    uint8_t mRightShift;  // The amount to right-shift after masking.
+    uint8_t mBitWidth;    // The width (in bits) of the value.
+
+    /// Sets the mask (and thus the right-shift and bit-width as well).
+    void Set(uint32_t aMask);
+
+   public:
+    Value() {
+      mMask = 0;
+      mRightShift = 0;
+      mBitWidth = 0;
+    }
+
+    /// Returns true if this channel is used. Only used for alpha.
+    bool IsPresent() const { return mMask != 0x0; }
+
+    /// Extracts the single color value from the multi-color value.
+    uint8_t Get(uint32_t aVal) const;
+
+    /// Like Get(), but specially for alpha.
+    uint8_t GetAlpha(uint32_t aVal, bool& aHasAlphaOut) const;
+
+    /// Specialized versions of Get() for when the bit-width is 5 or 8.
+    /// (They will assert if called and the bit-width is not 5 or 8.)
+    uint8_t Get5(uint32_t aVal) const;
+    uint8_t Get8(uint32_t aVal) const;
+  };
+
+ public:
+  /// The individual color channels.
+  Value mRed;
+  Value mGreen;
+  Value mBlue;
+  Value mAlpha;
+
+  /// Set bitfields to the standard 5-5-5 16bpp values.
+  void SetR5G5B5();
+
+  /// Set bitfields to the standard 8-8-8 32bpp values.
+  void SetR8G8B8();
+
+  /// Test if bitfields have the standard 5-5-5 16bpp values.
+  bool IsR5G5B5() const;
+
+  /// Test if bitfields have the standard 8-8-8 32bpp values.
+  bool IsR8G8B8() const;
+
+  /// Read the bitfields from a header. The reading of the alpha mask is
+  /// optional.
+  void ReadFromHeader(const char* aData, bool aReadAlpha);
+
+  /// Length of the bitfields structure in the BMP file.
+  static const size_t LENGTH = 12;
+};
+
+}  // namespace bmp
+
+class RasterImage;
+
+/// Decoder for BMP-Files, as used by Windows and OS/2.
+
+class nsBMPDecoder : public Decoder {
+ public:
+  ~nsBMPDecoder();
+
+  DecoderType GetType() const override { return DecoderType::BMP; }
+
+  /// @return true if this BMP is a valid ICO resource.
+  bool IsValidICOResource() const override { return true; }
+
+  /// Obtains the internal output image buffer.
+  uint32_t* GetImageData() { return reinterpret_cast<uint32_t*>(mImageData); }
+
+  /// Obtains the length of the internal output image buffer.
+  size_t GetImageDataLength() const { return mImageDataLength; }
+
+  /// Obtains the size of the compressed image resource.
+  int32_t GetCompressedImageSize() const;
+
+  /// Mark this BMP as being within an ICO file. Only used for testing purposes
+  /// because the ICO-specific constructor does this marking automatically.
+  void SetIsWithinICO() { mIsWithinICO = true; }
+
+  /// Did the BMP file have alpha data of any kind? (Only use this after the
+  /// bitmap has been fully decoded.)
+  bool HasTransparency() const { return mDoesHaveTransparency; }
+
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+  nsresult BeforeFinishInternal() override;
+  nsresult FinishInternal() override;
+
+ private:
+  friend class DecoderFactory;
+
+  enum class State {
+    FILE_HEADER,
+    INFO_HEADER_SIZE,
+    INFO_HEADER_REST,
+    BITFIELDS,
+    SKIP_TO_COLOR_PROFILE,
+    FOUND_COLOR_PROFILE,
+    COLOR_PROFILE,
+    ALLOCATE_SURFACE,
+    COLOR_TABLE,
+    GAP,
+    AFTER_GAP,
+    PIXEL_ROW,
+    RLE_SEGMENT,
+    RLE_DELTA,
+    RLE_ABSOLUTE
+  };
+
+  // This is the constructor used for normal and clipboard BMP images.
+  explicit nsBMPDecoder(RasterImage* aImage, bool aForClipboard = false);
+
+  // This is the constructor used for BMP resources in ICO images.
+  nsBMPDecoder(RasterImage* aImage, uint32_t aDataOffset);
+
+  // Helper constructor called by the other two.
+  nsBMPDecoder(RasterImage* aImage, State aState, size_t aLength,
+               bool aForClipboard);
+
+  int32_t AbsoluteHeight() const { return abs(mH.mHeight); }
+
+  uint32_t* RowBuffer();
+  void ClearRowBufferRemainder();
+
+  void FinishRow();
+
+  void PrepareCalibratedColorProfile();
+  void PrepareColorProfileTransform();
+
+  LexerTransition<State> ReadFileHeader(const char* aData, size_t aLength);
+  LexerTransition<State> ReadInfoHeaderSize(const char* aData, size_t aLength);
+  LexerTransition<State> ReadInfoHeaderRest(const char* aData, size_t aLength);
+  LexerTransition<State> ReadBitfields(const char* aData, size_t aLength);
+  LexerTransition<State> SeekColorProfile(size_t aLength);
+  LexerTransition<State> ReadColorProfile(const char* aData, size_t aLength);
+  LexerTransition<State> AllocateSurface();
+  LexerTransition<State> ReadColorTable(const char* aData, size_t aLength);
+  LexerTransition<State> SkipGap();
+  LexerTransition<State> AfterGap();
+  LexerTransition<State> ReadPixelRow(const char* aData);
+  LexerTransition<State> ReadRLESegment(const char* aData);
+  LexerTransition<State> ReadRLEDelta(const char* aData);
+  LexerTransition<State> ReadRLEAbsolute(const char* aData, size_t aLength);
+
+  SurfacePipe mPipe;
+
+  StreamingLexer<State> mLexer;
+
+  // Iterator to save return point.
+  Maybe<SourceBufferIterator> mReturnIterator;
+
+  UniquePtr<uint32_t[]> mRowBuffer;
+
+  bmp::Header mH;
+
+  // If the BMP is within an ICO file our treatment of it differs slightly.
+  bool mIsWithinICO;
+
+  // If the BMP decoded from the clipboard, we don't start with a data offset.
+  bool mIsForClipboard;
+
+  bmp::BitFields mBitFields;
+
+  // Might the image have transparency? Determined from the headers during
+  // metadata decode. (Does not guarantee the image actually has transparency.)
+  bool mMayHaveTransparency;
+
+  // Does the image have transparency? Determined during full decoding, so only
+  // use this after that has been completed.
+  bool mDoesHaveTransparency;
+
+  uint32_t mNumColors;  // The number of used colors, i.e. the number of
+                        // entries in mColors, if it's present.
+  UniquePtr<bmp::ColorTableEntry[]>
+      mColors;              // The color table, if it's present.
+  uint32_t mBytesPerColor;  // 3 or 4, depending on the format
+
+  // The number of bytes prior to the optional gap that have been read. This
+  // is used to find the start of the pixel data.
+  uint32_t mPreGapLength;
+
+  uint32_t mPixelRowSize;  // The number of bytes per pixel row.
+
+  int32_t mCurrentRow;  // Index of the row of the image that's currently
+                        // being decoded: [height,1].
+  int32_t mCurrentPos;  // Index into the current line. Used when
+                        // doing RLE decoding and when filling in pixels
+                        // for truncated files.
+
+  // Only used in RLE_ABSOLUTE state: the number of pixels to read.
+  uint32_t mAbsoluteModeNumPixels;
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsBMPDecoder_h
diff --git a/image/decoders/nsGIFDecoder2.cpp b/image/decoders/nsGIFDecoder2.cpp
new file mode 100644
index 0000000000..38b1b1eef6
--- /dev/null
+++ b/image/decoders/nsGIFDecoder2.cpp
@@ -0,0 +1,1073 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+/*
+The Graphics Interchange Format(c) is the copyright property of CompuServe
+Incorporated. Only CompuServe Incorporated is authorized to define, redefine,
+enhance, alter, modify or change in any way the definition of the format.
+
+CompuServe Incorporated hereby grants a limited, non-exclusive, royalty-free
+license for the use of the Graphics Interchange Format(sm) in computer
+software; computer software utilizing GIF(sm) must acknowledge ownership of the
+Graphics Interchange Format and its Service Mark by CompuServe Incorporated, in
+User and Technical Documentation. Computer software utilizing GIF, which is
+distributed or may be distributed without User or Technical Documentation must
+display to the screen or printer a message acknowledging ownership of the
+Graphics Interchange Format and the Service Mark by CompuServe Incorporated; in
+this case, the acknowledgement may be displayed in an opening screen or leading
+banner, or a closing screen or trailing banner. A message such as the following
+may be used:
+
+    "The Graphics Interchange Format(c) is the Copyright property of
+    CompuServe Incorporated. GIF(sm) is a Service Mark property of
+    CompuServe Incorporated."
+
+For further information, please contact :
+
+    CompuServe Incorporated
+    Graphics Technology Department
+    5000 Arlington Center Boulevard
+    Columbus, Ohio  43220
+    U. S. A.
+
+CompuServe Incorporated maintains a mailing list with all those individuals and
+organizations who wish to receive copies of this document when it is corrected
+or revised. This service is offered free of charge; please provide us with your
+mailing address.
+*/
+
+#include "nsGIFDecoder2.h"
+
+#include <stddef.h>
+
+#include "imgFrame.h"
+#include "mozilla/EndianUtils.h"
+#include "RasterImage.h"
+#include "SurfacePipeFactory.h"
+
+#include "gfxColor.h"
+#include "gfxPlatform.h"
+#include "qcms.h"
+#include <algorithm>
+#include "mozilla/Telemetry.h"
+
+using namespace mozilla::gfx;
+
+using std::max;
+
+namespace mozilla {
+namespace image {
+
+//////////////////////////////////////////////////////////////////////
+// GIF Decoder Implementation
+
+static const size_t GIF_HEADER_LEN = 6;
+static const size_t GIF_SCREEN_DESCRIPTOR_LEN = 7;
+static const size_t BLOCK_HEADER_LEN = 1;
+static const size_t SUB_BLOCK_HEADER_LEN = 1;
+static const size_t EXTENSION_HEADER_LEN = 2;
+static const size_t GRAPHIC_CONTROL_EXTENSION_LEN = 4;
+static const size_t APPLICATION_EXTENSION_LEN = 11;
+static const size_t IMAGE_DESCRIPTOR_LEN = 9;
+
+// Masks for reading color table information from packed fields in the screen
+// descriptor and image descriptor blocks.
+static const uint8_t PACKED_FIELDS_COLOR_TABLE_BIT = 0x80;
+static const uint8_t PACKED_FIELDS_INTERLACED_BIT = 0x40;
+static const uint8_t PACKED_FIELDS_TABLE_DEPTH_MASK = 0x07;
+
+nsGIFDecoder2::nsGIFDecoder2(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::To(State::GIF_HEADER, GIF_HEADER_LEN),
+             Transition::TerminateSuccess()),
+      mOldColor(0),
+      mCurrentFrameIndex(-1),
+      mColorTablePos(0),
+      mColormap(nullptr),
+      mColormapSize(0),
+      mColorMask('\0'),
+      mGIFOpen(false),
+      mSawTransparency(false),
+      mSwizzleFn(nullptr) {
+  // Clear out the structure, excluding the arrays. Ensure that the global
+  // colormap is initialized as opaque.
+  memset(&mGIFStruct, 0, sizeof(mGIFStruct));
+  memset(mGIFStruct.global_colormap, 0xFF, sizeof(mGIFStruct.global_colormap));
+
+  // Each color table will need to be unpacked.
+  mSwizzleFn = SwizzleRow(SurfaceFormat::R8G8B8, SurfaceFormat::OS_RGBA);
+  MOZ_ASSERT(mSwizzleFn);
+}
+
+nsGIFDecoder2::~nsGIFDecoder2() { free(mGIFStruct.local_colormap); }
+
+nsresult nsGIFDecoder2::FinishInternal() {
+  MOZ_ASSERT(!HasError(), "Shouldn't call FinishInternal after error!");
+
+  // If the GIF got cut off, handle it anyway
+  if (!IsMetadataDecode() && mGIFOpen) {
+    if (mCurrentFrameIndex == mGIFStruct.images_decoded) {
+      EndImageFrame();
+    }
+    PostDecodeDone(mGIFStruct.loop_count);
+    mGIFOpen = false;
+  }
+
+  return NS_OK;
+}
+
+void nsGIFDecoder2::FlushImageData() {
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (!invalidRect) {
+    return;
+  }
+
+  PostInvalidation(invalidRect->mInputSpaceRect,
+                   Some(invalidRect->mOutputSpaceRect));
+}
+
+//******************************************************************************
+// GIF decoder callback methods. Part of public API for GIF2
+//******************************************************************************
+
+//******************************************************************************
+void nsGIFDecoder2::BeginGIF() {
+  if (mGIFOpen) {
+    return;
+  }
+
+  mGIFOpen = true;
+
+  PostSize(mGIFStruct.screen_width, mGIFStruct.screen_height);
+}
+
+bool nsGIFDecoder2::CheckForTransparency(const OrientedIntRect& aFrameRect) {
+  // Check if the image has a transparent color in its palette.
+  if (mGIFStruct.is_transparent) {
+    PostHasTransparency();
+    return true;
+  }
+
+  // This is a bit of a hack. Some sites will use a 1x1 gif that includes no
+  // header information indicating it is transparent, no palette, and no image
+  // data at all (so no pixels get written) to represent a transparent pixel
+  // using the absolute least number of bytes. Generally things are setup to
+  // detect transparency without decoding the image data. So to detect this kind
+  // of transparency without decoing the image data we would have to assume
+  // every gif is transparent, which we would like to avoid. Changing things so
+  // that we can detect transparency at any point of decoding is a bigger change
+  // and not worth it for one questionable 1x1 gif. Using this "trick" for
+  // anything but 1x1 transparent spacer gifs doesn't make sense, so it's
+  // reasonable to target 1x1 gifs just for this.
+  if (mGIFStruct.screen_width == 1 && mGIFStruct.screen_height == 1) {
+    PostHasTransparency();
+    return true;
+  }
+
+  if (mGIFStruct.images_decoded > 0) {
+    return false;  // We only care about first frame padding below.
+  }
+
+  // If we need padding on the first frame, that means we don't draw into part
+  // of the image at all. Report that as transparency.
+  OrientedIntRect imageRect(0, 0, mGIFStruct.screen_width,
+                            mGIFStruct.screen_height);
+  if (!imageRect.IsEqualEdges(aFrameRect)) {
+    PostHasTransparency();
+    mSawTransparency = true;  // Make sure we don't optimize it away.
+    return true;
+  }
+
+  return false;
+}
+
+//******************************************************************************
+nsresult nsGIFDecoder2::BeginImageFrame(const OrientedIntRect& aFrameRect,
+                                        uint16_t aDepth, bool aIsInterlaced) {
+  MOZ_ASSERT(HasSize());
+
+  bool hasTransparency = CheckForTransparency(aFrameRect);
+
+  // Make sure there's no animation if we're downscaling.
+  MOZ_ASSERT_IF(Size() != OutputSize(), !GetImageMetadata().HasAnimation());
+
+  Maybe<AnimationParams> animParams;
+  if (!IsFirstFrameDecode()) {
+    animParams.emplace(aFrameRect.ToUnknownRect(),
+                       FrameTimeout::FromRawMilliseconds(mGIFStruct.delay_time),
+                       uint32_t(mGIFStruct.images_decoded), BlendMethod::OVER,
+                       DisposalMethod(mGIFStruct.disposal_method));
+  }
+
+  SurfacePipeFlags pipeFlags =
+      aIsInterlaced ? SurfacePipeFlags::DEINTERLACE : SurfacePipeFlags();
+
+  gfx::SurfaceFormat format;
+  if (mGIFStruct.images_decoded == 0) {
+    // The first frame may be displayed progressively.
+    pipeFlags |= SurfacePipeFlags::PROGRESSIVE_DISPLAY;
+
+    // Only allow opaque surfaces if we are decoding a single image without
+    // transparency. For an animation, there isn't much benefit to RGBX given
+    // the current frame is constantly changing, and there are many risks
+    // since BlendAnimationFilter is able to clear rows of data.
+    format = hasTransparency || animParams ? SurfaceFormat::OS_RGBA
+                                           : SurfaceFormat::OS_RGBX;
+  } else {
+    format = SurfaceFormat::OS_RGBA;
+  }
+
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), aFrameRect, format, format, animParams,
+      mTransform, pipeFlags);
+  mCurrentFrameIndex = mGIFStruct.images_decoded;
+
+  if (!pipe) {
+    mPipe = SurfacePipe();
+    return NS_ERROR_FAILURE;
+  }
+
+  mPipe = std::move(*pipe);
+  return NS_OK;
+}
+
+//******************************************************************************
+void nsGIFDecoder2::EndImageFrame() {
+  Opacity opacity = Opacity::SOME_TRANSPARENCY;
+
+  if (mGIFStruct.images_decoded == 0) {
+    // We need to send invalidations for the first frame.
+    FlushImageData();
+
+    // The first frame was preallocated with alpha; if it wasn't transparent, we
+    // should fix that. We can also mark it opaque unconditionally if we didn't
+    // actually see any transparent pixels - this test is only valid for the
+    // first frame.
+    if (!mGIFStruct.is_transparent && !mSawTransparency) {
+      opacity = Opacity::FULLY_OPAQUE;
+    }
+  }
+
+  // Unconditionally increment images_decoded, because we unconditionally
+  // append frames in BeginImageFrame(). This ensures that images_decoded
+  // always refers to the frame in mImage we're currently decoding,
+  // even if some of them weren't decoded properly and thus are blank.
+  mGIFStruct.images_decoded++;
+
+  // Reset graphic control extension parameters that we shouldn't reuse
+  // between frames.
+  mGIFStruct.delay_time = 0;
+
+  // Tell the superclass we finished a frame
+  PostFrameStop(opacity);
+
+  // Reset the transparent pixel
+  if (mOldColor) {
+    mColormap[mGIFStruct.tpixel] = mOldColor;
+    mOldColor = 0;
+  }
+
+  mColormap = nullptr;
+  mColormapSize = 0;
+  mCurrentFrameIndex = -1;
+}
+
+template <typename PixelSize>
+PixelSize nsGIFDecoder2::ColormapIndexToPixel(uint8_t aIndex) {
+  MOZ_ASSERT(sizeof(PixelSize) == sizeof(uint32_t));
+
+  // Retrieve the next color, clamping to the size of the colormap.
+  uint32_t color = mColormap[aIndex & mColorMask];
+
+  // Check for transparency.
+  if (mGIFStruct.is_transparent) {
+    mSawTransparency = mSawTransparency || color == 0;
+  }
+
+  return color;
+}
+
+template <>
+uint8_t nsGIFDecoder2::ColormapIndexToPixel<uint8_t>(uint8_t aIndex) {
+  return aIndex & mColorMask;
+}
+
+template <typename PixelSize>
+Tuple<int32_t, Maybe<WriteState>> nsGIFDecoder2::YieldPixels(
+    const uint8_t* aData, size_t aLength, size_t* aBytesReadOut,
+    PixelSize* aPixelBlock, int32_t aBlockSize) {
+  MOZ_ASSERT(aData);
+  MOZ_ASSERT(aBytesReadOut);
+  MOZ_ASSERT(mGIFStruct.stackp >= mGIFStruct.stack);
+
+  // Advance to the next byte we should read.
+  const uint8_t* data = aData + *aBytesReadOut;
+
+  int32_t written = 0;
+  while (aBlockSize > written) {
+    // If we don't have any decoded data to yield, try to read some input and
+    // produce some.
+    if (mGIFStruct.stackp == mGIFStruct.stack) {
+      while (mGIFStruct.bits < mGIFStruct.codesize &&
+             *aBytesReadOut < aLength) {
+        // Feed the next byte into the decoder's 32-bit input buffer.
+        mGIFStruct.datum += int32_t(*data) << mGIFStruct.bits;
+        mGIFStruct.bits += 8;
+        data += 1;
+        *aBytesReadOut += 1;
+      }
+
+      if (mGIFStruct.bits < mGIFStruct.codesize) {
+        return MakeTuple(written, Some(WriteState::NEED_MORE_DATA));
+      }
+
+      // Get the leading variable-length symbol from the data stream.
+      int code = mGIFStruct.datum & mGIFStruct.codemask;
+      mGIFStruct.datum >>= mGIFStruct.codesize;
+      mGIFStruct.bits -= mGIFStruct.codesize;
+
+      const int clearCode = ClearCode();
+
+      // Reset the dictionary to its original state, if requested
+      if (code == clearCode) {
+        mGIFStruct.codesize = mGIFStruct.datasize + 1;
+        mGIFStruct.codemask = (1 << mGIFStruct.codesize) - 1;
+        mGIFStruct.avail = clearCode + 2;
+        mGIFStruct.oldcode = -1;
+        return MakeTuple(written, Some(WriteState::NEED_MORE_DATA));
+      }
+
+      // Check for explicit end-of-stream code. It should only appear after all
+      // image data, but if that was the case we wouldn't be in this function,
+      // so this is always an error condition.
+      if (code == (clearCode + 1)) {
+        return MakeTuple(written, Some(WriteState::FAILURE));
+      }
+
+      if (mGIFStruct.oldcode == -1) {
+        if (code >= MAX_BITS) {
+          // The code's too big; something's wrong.
+          return MakeTuple(written, Some(WriteState::FAILURE));
+        }
+
+        mGIFStruct.firstchar = mGIFStruct.oldcode = code;
+
+        // Yield a pixel at the appropriate index in the colormap.
+        mGIFStruct.pixels_remaining--;
+        aPixelBlock[written++] =
+            ColormapIndexToPixel<PixelSize>(mGIFStruct.suffix[code]);
+        continue;
+      }
+
+      int incode = code;
+      if (code >= mGIFStruct.avail) {
+        *mGIFStruct.stackp++ = mGIFStruct.firstchar;
+        code = mGIFStruct.oldcode;
+
+        if (mGIFStruct.stackp >= mGIFStruct.stack + MAX_BITS) {
+          // Stack overflow; something's wrong.
+          return MakeTuple(written, Some(WriteState::FAILURE));
+        }
+      }
+
+      while (code >= clearCode) {
+        if ((code >= MAX_BITS) || (code == mGIFStruct.prefix[code])) {
+          return MakeTuple(written, Some(WriteState::FAILURE));
+        }
+
+        *mGIFStruct.stackp++ = mGIFStruct.suffix[code];
+        code = mGIFStruct.prefix[code];
+
+        if (mGIFStruct.stackp >= mGIFStruct.stack + MAX_BITS) {
+          // Stack overflow; something's wrong.
+          return MakeTuple(written, Some(WriteState::FAILURE));
+        }
+      }
+
+      *mGIFStruct.stackp++ = mGIFStruct.firstchar = mGIFStruct.suffix[code];
+
+      // Define a new codeword in the dictionary.
+      if (mGIFStruct.avail < 4096) {
+        mGIFStruct.prefix[mGIFStruct.avail] = mGIFStruct.oldcode;
+        mGIFStruct.suffix[mGIFStruct.avail] = mGIFStruct.firstchar;
+        mGIFStruct.avail++;
+
+        // If we've used up all the codewords of a given length increase the
+        // length of codewords by one bit, but don't exceed the specified
+        // maximum codeword size of 12 bits.
+        if (((mGIFStruct.avail & mGIFStruct.codemask) == 0) &&
+            (mGIFStruct.avail < 4096)) {
+          mGIFStruct.codesize++;
+          mGIFStruct.codemask += mGIFStruct.avail;
+        }
+      }
+
+      mGIFStruct.oldcode = incode;
+    }
+
+    if (MOZ_UNLIKELY(mGIFStruct.stackp <= mGIFStruct.stack)) {
+      MOZ_ASSERT_UNREACHABLE("No decoded data but we didn't return early?");
+      return MakeTuple(written, Some(WriteState::FAILURE));
+    }
+
+    // Yield a pixel at the appropriate index in the colormap.
+    mGIFStruct.pixels_remaining--;
+    aPixelBlock[written++] =
+        ColormapIndexToPixel<PixelSize>(*--mGIFStruct.stackp);
+  }
+
+  return MakeTuple(written, Maybe<WriteState>());
+}
+
+/// Expand the colormap from RGB to Packed ARGB as needed by Cairo.
+/// And apply any LCMS transformation.
+void nsGIFDecoder2::ConvertColormap(uint32_t* aColormap, uint32_t aColors) {
+  if (!aColors) {
+    return;
+  }
+
+  // Apply CMS transformation if enabled and available
+  if (mCMSMode == CMSMode::All) {
+    qcms_transform* transform = GetCMSsRGBTransform(SurfaceFormat::R8G8B8);
+    if (transform) {
+      qcms_transform_data(transform, aColormap, aColormap, aColors);
+    }
+  }
+
+  // Expand color table from RGB to BGRA.
+  MOZ_ASSERT(mSwizzleFn);
+  uint8_t* data = reinterpret_cast<uint8_t*>(aColormap);
+  mSwizzleFn(data, data, aColors);
+}
+
+LexerResult nsGIFDecoder2::DoDecode(SourceBufferIterator& aIterator,
+                                    IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(
+      aIterator, aOnResume,
+      [=](State aState, const char* aData, size_t aLength) {
+        switch (aState) {
+          case State::GIF_HEADER:
+            return ReadGIFHeader(aData);
+          case State::SCREEN_DESCRIPTOR:
+            return ReadScreenDescriptor(aData);
+          case State::GLOBAL_COLOR_TABLE:
+            return ReadGlobalColorTable(aData, aLength);
+          case State::FINISHED_GLOBAL_COLOR_TABLE:
+            return FinishedGlobalColorTable();
+          case State::BLOCK_HEADER:
+            return ReadBlockHeader(aData);
+          case State::EXTENSION_HEADER:
+            return ReadExtensionHeader(aData);
+          case State::GRAPHIC_CONTROL_EXTENSION:
+            return ReadGraphicControlExtension(aData);
+          case State::APPLICATION_IDENTIFIER:
+            return ReadApplicationIdentifier(aData);
+          case State::NETSCAPE_EXTENSION_SUB_BLOCK:
+            return ReadNetscapeExtensionSubBlock(aData);
+          case State::NETSCAPE_EXTENSION_DATA:
+            return ReadNetscapeExtensionData(aData);
+          case State::IMAGE_DESCRIPTOR:
+            return ReadImageDescriptor(aData);
+          case State::FINISH_IMAGE_DESCRIPTOR:
+            return FinishImageDescriptor(aData);
+          case State::LOCAL_COLOR_TABLE:
+            return ReadLocalColorTable(aData, aLength);
+          case State::FINISHED_LOCAL_COLOR_TABLE:
+            return FinishedLocalColorTable();
+          case State::IMAGE_DATA_BLOCK:
+            return ReadImageDataBlock(aData);
+          case State::IMAGE_DATA_SUB_BLOCK:
+            return ReadImageDataSubBlock(aData);
+          case State::LZW_DATA:
+            return ReadLZWData(aData, aLength);
+          case State::SKIP_LZW_DATA:
+            return Transition::ContinueUnbuffered(State::SKIP_LZW_DATA);
+          case State::FINISHED_LZW_DATA:
+            return Transition::To(State::IMAGE_DATA_SUB_BLOCK,
+                                  SUB_BLOCK_HEADER_LEN);
+          case State::SKIP_SUB_BLOCKS:
+            return SkipSubBlocks(aData);
+          case State::SKIP_DATA_THEN_SKIP_SUB_BLOCKS:
+            return Transition::ContinueUnbuffered(
+                State::SKIP_DATA_THEN_SKIP_SUB_BLOCKS);
+          case State::FINISHED_SKIPPING_DATA:
+            return Transition::To(State::SKIP_SUB_BLOCKS, SUB_BLOCK_HEADER_LEN);
+          default:
+            MOZ_CRASH("Unknown State");
+        }
+      });
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadGIFHeader(
+    const char* aData) {
+  // We retrieve the version here but because many GIF encoders set header
+  // fields incorrectly, we barely use it; features which should only appear in
+  // GIF89a are always accepted.
+  if (strncmp(aData, "GIF87a", GIF_HEADER_LEN) == 0) {
+    mGIFStruct.version = 87;
+  } else if (strncmp(aData, "GIF89a", GIF_HEADER_LEN) == 0) {
+    mGIFStruct.version = 89;
+  } else {
+    return Transition::TerminateFailure();
+  }
+
+  return Transition::To(State::SCREEN_DESCRIPTOR, GIF_SCREEN_DESCRIPTOR_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadScreenDescriptor(
+    const char* aData) {
+  mGIFStruct.screen_width = LittleEndian::readUint16(aData + 0);
+  mGIFStruct.screen_height = LittleEndian::readUint16(aData + 2);
+
+  const uint8_t packedFields = aData[4];
+
+  // XXX: Should we be capturing these values even if there is no global color
+  // table?
+  mGIFStruct.global_colormap_depth =
+      (packedFields & PACKED_FIELDS_TABLE_DEPTH_MASK) + 1;
+  mGIFStruct.global_colormap_count = 1 << mGIFStruct.global_colormap_depth;
+
+  // We ignore several fields in the header. We don't care about the 'sort
+  // flag', which indicates if the global color table's entries are sorted in
+  // order of importance - if we need to render this image for a device with a
+  // narrower color gamut than GIF supports we'll handle that at a different
+  // layer. We have no use for the pixel aspect ratio as well. Finally, we
+  // intentionally ignore the background color index, as implementing that
+  // feature would not be web compatible - when a GIF image frame doesn't cover
+  // the entire area of the image, the area that's not covered should always be
+  // transparent.
+
+  if (packedFields & PACKED_FIELDS_COLOR_TABLE_BIT) {
+    MOZ_ASSERT(mColorTablePos == 0);
+
+    // We read the global color table in unbuffered mode since it can be quite
+    // large and it'd be preferable to avoid unnecessary copies.
+    const size_t globalColorTableSize = 3 * mGIFStruct.global_colormap_count;
+    return Transition::ToUnbuffered(State::FINISHED_GLOBAL_COLOR_TABLE,
+                                    State::GLOBAL_COLOR_TABLE,
+                                    globalColorTableSize);
+  }
+
+  return Transition::To(State::BLOCK_HEADER, BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadGlobalColorTable(
+    const char* aData, size_t aLength) {
+  uint8_t* dest =
+      reinterpret_cast<uint8_t*>(mGIFStruct.global_colormap) + mColorTablePos;
+  memcpy(dest, aData, aLength);
+  mColorTablePos += aLength;
+  return Transition::ContinueUnbuffered(State::GLOBAL_COLOR_TABLE);
+}
+
+LexerTransition<nsGIFDecoder2::State>
+nsGIFDecoder2::FinishedGlobalColorTable() {
+  ConvertColormap(mGIFStruct.global_colormap, mGIFStruct.global_colormap_count);
+  mColorTablePos = 0;
+  return Transition::To(State::BLOCK_HEADER, BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadBlockHeader(
+    const char* aData) {
+  // Determine what type of block we're dealing with.
+  switch (aData[0]) {
+    case GIF_EXTENSION_INTRODUCER:
+      return Transition::To(State::EXTENSION_HEADER, EXTENSION_HEADER_LEN);
+
+    case GIF_IMAGE_SEPARATOR:
+      return Transition::To(State::IMAGE_DESCRIPTOR, IMAGE_DESCRIPTOR_LEN);
+
+    case GIF_TRAILER:
+      FinishInternal();
+      return Transition::TerminateSuccess();
+
+    default:
+      // If we get anything other than GIF_IMAGE_SEPARATOR,
+      // GIF_EXTENSION_INTRODUCER, or GIF_TRAILER, there is extraneous data
+      // between blocks. The GIF87a spec tells us to keep reading until we find
+      // an image separator, but GIF89a says such a file is corrupt. We follow
+      // GIF89a and bail out.
+
+      if (mGIFStruct.images_decoded > 0) {
+        // The file is corrupt, but we successfully decoded some frames, so we
+        // may as well consider the decode successful and display them.
+        FinishInternal();
+        return Transition::TerminateSuccess();
+      }
+
+      // No images decoded; there is nothing to display.
+      return Transition::TerminateFailure();
+  }
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadExtensionHeader(
+    const char* aData) {
+  const uint8_t label = aData[0];
+  const uint8_t extensionHeaderLength = aData[1];
+
+  // If the extension header is zero length, just treat it as a block terminator
+  // and move on to the next block immediately.
+  if (extensionHeaderLength == 0) {
+    return Transition::To(State::BLOCK_HEADER, BLOCK_HEADER_LEN);
+  }
+
+  switch (label) {
+    case GIF_GRAPHIC_CONTROL_LABEL:
+      // The GIF spec mandates that the Control Extension header block length is
+      // 4 bytes, and the parser for this block reads 4 bytes, so we must
+      // enforce that the buffer contains at least this many bytes. If the GIF
+      // specifies a different length, we allow that, so long as it's larger;
+      // the additional data will simply be ignored.
+      return Transition::To(
+          State::GRAPHIC_CONTROL_EXTENSION,
+          max<uint8_t>(extensionHeaderLength, GRAPHIC_CONTROL_EXTENSION_LEN));
+
+    case GIF_APPLICATION_EXTENSION_LABEL:
+      // Again, the spec specifies that an application extension header is 11
+      // bytes, but for compatibility with GIFs in the wild, we allow deviation
+      // from the spec. This is important for real-world compatibility, as GIFs
+      // in the wild exist with application extension headers that are both
+      // shorter and longer than 11 bytes. However, we only try to actually
+      // interpret the application extension if the length is correct;
+      // otherwise, we just skip the block unconditionally.
+      return extensionHeaderLength == APPLICATION_EXTENSION_LEN
+                 ? Transition::To(State::APPLICATION_IDENTIFIER,
+                                  extensionHeaderLength)
+                 : Transition::ToUnbuffered(
+                       State::FINISHED_SKIPPING_DATA,
+                       State::SKIP_DATA_THEN_SKIP_SUB_BLOCKS,
+                       extensionHeaderLength);
+
+    default:
+      // Skip over any other type of extension block, including comment and
+      // plain text blocks.
+      return Transition::ToUnbuffered(State::FINISHED_SKIPPING_DATA,
+                                      State::SKIP_DATA_THEN_SKIP_SUB_BLOCKS,
+                                      extensionHeaderLength);
+  }
+}
+
+LexerTransition<nsGIFDecoder2::State>
+nsGIFDecoder2::ReadGraphicControlExtension(const char* aData) {
+  mGIFStruct.is_transparent = aData[0] & 0x1;
+  mGIFStruct.tpixel = uint8_t(aData[3]);
+  mGIFStruct.disposal_method = (aData[0] >> 2) & 0x7;
+
+  if (mGIFStruct.disposal_method == 4) {
+    // Some encoders (and apparently some specs) represent
+    // DisposalMethod::RESTORE_PREVIOUS as 4, but 3 is used in the canonical
+    // spec and is more popular, so we normalize to 3.
+    mGIFStruct.disposal_method = 3;
+  } else if (mGIFStruct.disposal_method > 4) {
+    // This GIF is using a disposal method which is undefined in the spec.
+    // Treat it as DisposalMethod::NOT_SPECIFIED.
+    mGIFStruct.disposal_method = 0;
+  }
+
+  DisposalMethod method = DisposalMethod(mGIFStruct.disposal_method);
+  if (method == DisposalMethod::CLEAR_ALL || method == DisposalMethod::CLEAR) {
+    // We may have to display the background under this image during animation
+    // playback, so we regard it as transparent.
+    PostHasTransparency();
+  }
+
+  mGIFStruct.delay_time = LittleEndian::readUint16(aData + 1) * 10;
+  if (!HasAnimation() && mGIFStruct.delay_time > 0) {
+    PostIsAnimated(FrameTimeout::FromRawMilliseconds(mGIFStruct.delay_time));
+  }
+
+  return Transition::To(State::SKIP_SUB_BLOCKS, SUB_BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadApplicationIdentifier(
+    const char* aData) {
+  if ((strncmp(aData, "NETSCAPE2.0", 11) == 0) ||
+      (strncmp(aData, "ANIMEXTS1.0", 11) == 0)) {
+    // This is a Netscape application extension block.
+    return Transition::To(State::NETSCAPE_EXTENSION_SUB_BLOCK,
+                          SUB_BLOCK_HEADER_LEN);
+  }
+
+  // This is an application extension we don't care about. Just skip it.
+  return Transition::To(State::SKIP_SUB_BLOCKS, SUB_BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State>
+nsGIFDecoder2::ReadNetscapeExtensionSubBlock(const char* aData) {
+  const uint8_t blockLength = aData[0];
+  if (blockLength == 0) {
+    // We hit the block terminator.
+    return Transition::To(State::BLOCK_HEADER, BLOCK_HEADER_LEN);
+  }
+
+  // We consume a minimum of 3 bytes in accordance with the specs for the
+  // Netscape application extension block, such as they are.
+  const size_t extensionLength = max<uint8_t>(blockLength, 3);
+  return Transition::To(State::NETSCAPE_EXTENSION_DATA, extensionLength);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadNetscapeExtensionData(
+    const char* aData) {
+  // Documentation for NETSCAPE2.0 / ANIMEXTS1.0 extensions can be found at:
+  //   https://wiki.whatwg.org/wiki/GIF
+  static const uint8_t NETSCAPE_LOOPING_EXTENSION_SUB_BLOCK_ID = 1;
+  static const uint8_t NETSCAPE_BUFFERING_EXTENSION_SUB_BLOCK_ID = 2;
+
+  const uint8_t subBlockID = aData[0] & 7;
+  switch (subBlockID) {
+    case NETSCAPE_LOOPING_EXTENSION_SUB_BLOCK_ID:
+      // This is looping extension.
+      mGIFStruct.loop_count = LittleEndian::readUint16(aData + 1);
+      // Zero loop count is infinite animation loop request.
+      if (mGIFStruct.loop_count == 0) {
+        mGIFStruct.loop_count = -1;
+      }
+
+      return Transition::To(State::NETSCAPE_EXTENSION_SUB_BLOCK,
+                            SUB_BLOCK_HEADER_LEN);
+
+    case NETSCAPE_BUFFERING_EXTENSION_SUB_BLOCK_ID:
+      // We allow, but ignore, this extension.
+      return Transition::To(State::NETSCAPE_EXTENSION_SUB_BLOCK,
+                            SUB_BLOCK_HEADER_LEN);
+
+    default:
+      return Transition::TerminateFailure();
+  }
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadImageDescriptor(
+    const char* aData) {
+  // On the first frame, we don't need to yield, and none of the other checks
+  // below apply, so we can just jump right into FinishImageDescriptor().
+  if (mGIFStruct.images_decoded == 0) {
+    return FinishImageDescriptor(aData);
+  }
+
+  if (!HasAnimation()) {
+    // We should've already called PostIsAnimated(); this must be a corrupt
+    // animated image with a first frame timeout of zero. Signal that we're
+    // animated now, before the first-frame decode early exit below, so that
+    // RasterImage can detect that this happened.
+    PostIsAnimated(FrameTimeout::FromRawMilliseconds(0));
+  }
+
+  if (IsFirstFrameDecode()) {
+    // We're about to get a second frame, but we only want the first. Stop
+    // decoding now.
+    FinishInternal();
+    return Transition::TerminateSuccess();
+  }
+
+  MOZ_ASSERT(Size() == OutputSize(), "Downscaling an animated image?");
+
+  // Yield to allow access to the previous frame before we start a new one.
+  return Transition::ToAfterYield(State::FINISH_IMAGE_DESCRIPTOR);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::FinishImageDescriptor(
+    const char* aData) {
+  OrientedIntRect frameRect;
+
+  // Get image offsets with respect to the screen origin.
+  frameRect.SetRect(
+      LittleEndian::readUint16(aData + 0), LittleEndian::readUint16(aData + 2),
+      LittleEndian::readUint16(aData + 4), LittleEndian::readUint16(aData + 6));
+
+  if (!mGIFStruct.images_decoded) {
+    // Work around GIF files where
+    //   * at least one of the logical screen dimensions is smaller than the
+    //     same dimension in the first image, or
+    //   * GIF87a files where the first image's dimensions do not match the
+    //     logical screen dimensions.
+    if (mGIFStruct.screen_height < frameRect.Height() ||
+        mGIFStruct.screen_width < frameRect.Width() ||
+        mGIFStruct.version == 87) {
+      mGIFStruct.screen_height = frameRect.Height();
+      mGIFStruct.screen_width = frameRect.Width();
+      frameRect.MoveTo(0, 0);
+    }
+
+    // Create the image container with the right size.
+    BeginGIF();
+    if (HasError()) {
+      // Setting the size led to an error.
+      return Transition::TerminateFailure();
+    }
+
+    // If we're doing a metadata decode, we're done.
+    if (IsMetadataDecode()) {
+      CheckForTransparency(frameRect);
+      FinishInternal();
+      return Transition::TerminateSuccess();
+    }
+  }
+
+  // Work around broken GIF files that have zero frame width or height; in this
+  // case, we'll treat the frame as having the same size as the overall image.
+  if (frameRect.Height() == 0 || frameRect.Width() == 0) {
+    frameRect.SetHeight(mGIFStruct.screen_height);
+    frameRect.SetWidth(mGIFStruct.screen_width);
+
+    // If that still resulted in zero frame width or height, give up.
+    if (frameRect.Height() == 0 || frameRect.Width() == 0) {
+      return Transition::TerminateFailure();
+    }
+  }
+
+  // Determine |depth| (log base 2 of the number of colors in the palette).
+  bool haveLocalColorTable = false;
+  uint16_t depth = 0;
+  uint8_t packedFields = aData[8];
+
+  if (packedFields & PACKED_FIELDS_COLOR_TABLE_BIT) {
+    // Get the palette depth from the local color table.
+    depth = (packedFields & PACKED_FIELDS_TABLE_DEPTH_MASK) + 1;
+    haveLocalColorTable = true;
+  } else {
+    // Get the palette depth from the global color table.
+    depth = mGIFStruct.global_colormap_depth;
+  }
+
+  // If the transparent color index is greater than the number of colors in the
+  // color table, we may need a higher color depth than |depth| would specify.
+  // Our internal representation of the image will instead use |realDepth|,
+  // which is the smallest color depth that can accommodate the existing palette
+  // *and* the transparent color index.
+  uint16_t realDepth = depth;
+  while (mGIFStruct.tpixel >= (1 << realDepth) && realDepth < 8) {
+    realDepth++;
+  }
+
+  // Create a mask used to ensure that color values fit within the colormap.
+  mColorMask = 0xFF >> (8 - realDepth);
+
+  // Determine if this frame is interlaced or not.
+  const bool isInterlaced = packedFields & PACKED_FIELDS_INTERLACED_BIT;
+
+  // Create the SurfacePipe we'll use to write output for this frame.
+  if (NS_FAILED(BeginImageFrame(frameRect, realDepth, isInterlaced))) {
+    return Transition::TerminateFailure();
+  }
+
+  // Clear state from last image.
+  mGIFStruct.pixels_remaining =
+      int64_t(frameRect.Width()) * int64_t(frameRect.Height());
+
+  if (haveLocalColorTable) {
+    // We have a local color table, so prepare to read it into the palette of
+    // the current frame.
+    mGIFStruct.local_colormap_size = 1 << depth;
+
+    if (!mColormap) {
+      // Ensure our current colormap buffer is large enough to hold the new one.
+      mColormapSize = sizeof(uint32_t) << realDepth;
+      if (mGIFStruct.local_colormap_buffer_size < mColormapSize) {
+        if (mGIFStruct.local_colormap) {
+          free(mGIFStruct.local_colormap);
+        }
+        mGIFStruct.local_colormap_buffer_size = mColormapSize;
+        mGIFStruct.local_colormap =
+            static_cast<uint32_t*>(moz_xmalloc(mColormapSize));
+        // Ensure the local colormap is initialized as opaque.
+        memset(mGIFStruct.local_colormap, 0xFF, mColormapSize);
+      } else {
+        mColormapSize = mGIFStruct.local_colormap_buffer_size;
+      }
+
+      mColormap = mGIFStruct.local_colormap;
+    }
+
+    MOZ_ASSERT(mColormap);
+
+    const size_t size = 3 << depth;
+    if (mColormapSize > size) {
+      // Clear the part of the colormap which will be unused with this palette.
+      // If a GIF references an invalid palette entry, ensure the entry is
+      // opaque white. This is needed for Skia as if it isn't, RGBX surfaces
+      // will cause blending issues with Skia.
+      memset(reinterpret_cast<uint8_t*>(mColormap) + size, 0xFF,
+             mColormapSize - size);
+    }
+
+    MOZ_ASSERT(mColorTablePos == 0);
+
+    // We read the local color table in unbuffered mode since it can be quite
+    // large and it'd be preferable to avoid unnecessary copies.
+    return Transition::ToUnbuffered(State::FINISHED_LOCAL_COLOR_TABLE,
+                                    State::LOCAL_COLOR_TABLE, size);
+  }
+
+  // There's no local color table; copy the global color table into the palette
+  // of the current frame.
+  if (mColormap) {
+    memcpy(mColormap, mGIFStruct.global_colormap, mColormapSize);
+  } else {
+    mColormap = mGIFStruct.global_colormap;
+  }
+
+  return Transition::To(State::IMAGE_DATA_BLOCK, BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadLocalColorTable(
+    const char* aData, size_t aLength) {
+  uint8_t* dest = reinterpret_cast<uint8_t*>(mColormap) + mColorTablePos;
+  memcpy(dest, aData, aLength);
+  mColorTablePos += aLength;
+  return Transition::ContinueUnbuffered(State::LOCAL_COLOR_TABLE);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::FinishedLocalColorTable() {
+  ConvertColormap(mColormap, mGIFStruct.local_colormap_size);
+  mColorTablePos = 0;
+  return Transition::To(State::IMAGE_DATA_BLOCK, BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadImageDataBlock(
+    const char* aData) {
+  // Make sure the transparent pixel is transparent in the colormap.
+  if (mGIFStruct.is_transparent) {
+    // Save the old value so we can restore it later.
+    if (mColormap == mGIFStruct.global_colormap) {
+      mOldColor = mColormap[mGIFStruct.tpixel];
+    }
+    mColormap[mGIFStruct.tpixel] = 0;
+  }
+
+  // Initialize the LZW decoder.
+  mGIFStruct.datasize = uint8_t(aData[0]);
+  if (mGIFStruct.datasize > MAX_LZW_BITS) {
+    return Transition::TerminateFailure();
+  }
+  const int clearCode = ClearCode();
+  if (clearCode >= MAX_BITS) {
+    return Transition::TerminateFailure();
+  }
+
+  mGIFStruct.avail = clearCode + 2;
+  mGIFStruct.oldcode = -1;
+  mGIFStruct.codesize = mGIFStruct.datasize + 1;
+  mGIFStruct.codemask = (1 << mGIFStruct.codesize) - 1;
+  mGIFStruct.datum = mGIFStruct.bits = 0;
+
+  // Initialize the tables.
+  for (int i = 0; i < clearCode; i++) {
+    mGIFStruct.suffix[i] = i;
+  }
+
+  mGIFStruct.stackp = mGIFStruct.stack;
+
+  // Begin reading image data sub-blocks.
+  return Transition::To(State::IMAGE_DATA_SUB_BLOCK, SUB_BLOCK_HEADER_LEN);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadImageDataSubBlock(
+    const char* aData) {
+  const uint8_t subBlockLength = aData[0];
+  if (subBlockLength == 0) {
+    // We hit the block terminator.
+    EndImageFrame();
+    return Transition::To(State::BLOCK_HEADER, BLOCK_HEADER_LEN);
+  }
+
+  if (mGIFStruct.pixels_remaining == 0) {
+    // We've already written to the entire image; we should've hit the block
+    // terminator at this point. This image is corrupt, but we'll tolerate it.
+
+    if (subBlockLength == GIF_TRAILER) {
+      // This GIF is missing the block terminator for the final block; we'll put
+      // up with it.
+      FinishInternal();
+      return Transition::TerminateSuccess();
+    }
+
+    // We're not at the end of the image, so just skip the extra data.
+    return Transition::ToUnbuffered(State::FINISHED_LZW_DATA,
+                                    State::SKIP_LZW_DATA, subBlockLength);
+  }
+
+  // Handle the standard case: there's data in the sub-block and pixels left to
+  // fill in the image. We read the sub-block unbuffered so we can get pixels on
+  // the screen as soon as possible.
+  return Transition::ToUnbuffered(State::FINISHED_LZW_DATA, State::LZW_DATA,
+                                  subBlockLength);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::ReadLZWData(
+    const char* aData, size_t aLength) {
+  const uint8_t* data = reinterpret_cast<const uint8_t*>(aData);
+  size_t length = aLength;
+
+  while (mGIFStruct.pixels_remaining > 0 &&
+         (length > 0 || mGIFStruct.bits >= mGIFStruct.codesize)) {
+    size_t bytesRead = 0;
+
+    auto result = mPipe.WritePixelBlocks<uint32_t>(
+        [&](uint32_t* aPixelBlock, int32_t aBlockSize) {
+          return YieldPixels<uint32_t>(data, length, &bytesRead, aPixelBlock,
+                                       aBlockSize);
+        });
+
+    if (MOZ_UNLIKELY(bytesRead > length)) {
+      MOZ_ASSERT_UNREACHABLE("Overread?");
+      bytesRead = length;
+    }
+
+    // Advance our position in the input based upon what YieldPixel() consumed.
+    data += bytesRead;
+    length -= bytesRead;
+
+    switch (result) {
+      case WriteState::NEED_MORE_DATA:
+        continue;
+
+      case WriteState::FINISHED:
+        NS_WARNING_ASSERTION(mGIFStruct.pixels_remaining <= 0,
+                             "too many pixels");
+        mGIFStruct.pixels_remaining = 0;
+        break;
+
+      case WriteState::FAILURE:
+        return Transition::TerminateFailure();
+    }
+  }
+
+  // We're done, but keep going until we consume all the data in the sub-block.
+  return Transition::ContinueUnbuffered(State::LZW_DATA);
+}
+
+LexerTransition<nsGIFDecoder2::State> nsGIFDecoder2::SkipSubBlocks(
+    const char* aData) {
+  // In the SKIP_SUB_BLOCKS state we skip over data sub-blocks that we're not
+  // interested in. Blocks consist of a block header (which can be up to 255
+  // bytes in length) and a series of data sub-blocks. Each data sub-block
+  // consists of a single byte length value, followed by the data itself. A data
+  // sub-block with a length of zero terminates the overall block.
+  // SKIP_SUB_BLOCKS reads a sub-block length value. If it's zero, we've arrived
+  // at the next block. Otherwise, we enter the SKIP_DATA_THEN_SKIP_SUB_BLOCKS
+  // state to skip over the sub-block data and return to SKIP_SUB_BLOCKS at the
+  // start of the next sub-block.
+
+  const uint8_t nextSubBlockLength = aData[0];
+  if (nextSubBlockLength == 0) {
+    // We hit the block terminator, so the sequence of data sub-blocks is over;
+    // begin processing another block.
+    return Transition::To(State::BLOCK_HEADER, BLOCK_HEADER_LEN);
+  }
+
+  // Skip to the next sub-block length value.
+  return Transition::ToUnbuffered(State::FINISHED_SKIPPING_DATA,
+                                  State::SKIP_DATA_THEN_SKIP_SUB_BLOCKS,
+                                  nextSubBlockLength);
+}
+
+Maybe<Telemetry::HistogramID> nsGIFDecoder2::SpeedHistogram() const {
+  return Some(Telemetry::IMAGE_DECODE_SPEED_GIF);
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsGIFDecoder2.h b/image/decoders/nsGIFDecoder2.h
new file mode 100644
index 0000000000..fb444fba7e
--- /dev/null
+++ b/image/decoders/nsGIFDecoder2.h
@@ -0,0 +1,166 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsGIFDecoder2_h
+#define mozilla_image_decoders_nsGIFDecoder2_h
+
+#include "Decoder.h"
+#include "GIF2.h"
+#include "StreamingLexer.h"
+#include "SurfacePipe.h"
+#include "mozilla/gfx/Swizzle.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+//////////////////////////////////////////////////////////////////////
+// nsGIFDecoder2 Definition
+
+class nsGIFDecoder2 : public Decoder {
+ public:
+  ~nsGIFDecoder2();
+
+  DecoderType GetType() const override { return DecoderType::GIF; }
+
+ protected:
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+  nsresult FinishInternal() override;
+
+  Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsGIFDecoder2(RasterImage* aImage);
+
+  /// Called when we begin decoding the image.
+  void BeginGIF();
+
+  /**
+   * Called when we begin decoding a frame.
+   *
+   * @param aFrameRect The region of the image that contains data. The region
+   *                   outside this rect is transparent.
+   * @param aDepth The palette depth of this frame.
+   * @param aIsInterlaced If true, this frame is an interlaced frame.
+   */
+  nsresult BeginImageFrame(const OrientedIntRect& aFrameRect, uint16_t aDepth,
+                           bool aIsInterlaced);
+
+  /// Called when we finish decoding a frame.
+  void EndImageFrame();
+
+  /// Called when we finish decoding the entire image.
+  void FlushImageData();
+
+  /// Convert color map to BGRA, applying any necessary CMS transforms.
+  void ConvertColormap(uint32_t* aColormap, uint32_t aColors);
+
+  /// Transforms a palette index into a pixel.
+  template <typename PixelSize>
+  PixelSize ColormapIndexToPixel(uint8_t aIndex);
+
+  /// A generator function that performs LZW decompression and yields pixels.
+  template <typename PixelSize>
+  Tuple<int32_t, Maybe<WriteState>> YieldPixels(const uint8_t* aData,
+                                                size_t aLength,
+                                                size_t* aBytesReadOut,
+                                                PixelSize* aPixelBlock,
+                                                int32_t aBlockSize);
+
+  /// Checks if we have transparency, either because the header indicates that
+  /// there's alpha, or because the frame rect doesn't cover the entire image.
+  bool CheckForTransparency(const OrientedIntRect& aFrameRect);
+
+  // @return the clear code used for LZW decompression.
+  int ClearCode() const {
+    MOZ_ASSERT(mGIFStruct.datasize <= MAX_LZW_BITS);
+    return 1 << mGIFStruct.datasize;
+  }
+
+  enum class State {
+    FAILURE,
+    SUCCESS,
+    GIF_HEADER,
+    SCREEN_DESCRIPTOR,
+    GLOBAL_COLOR_TABLE,
+    FINISHED_GLOBAL_COLOR_TABLE,
+    BLOCK_HEADER,
+    EXTENSION_HEADER,
+    GRAPHIC_CONTROL_EXTENSION,
+    APPLICATION_IDENTIFIER,
+    NETSCAPE_EXTENSION_SUB_BLOCK,
+    NETSCAPE_EXTENSION_DATA,
+    IMAGE_DESCRIPTOR,
+    FINISH_IMAGE_DESCRIPTOR,
+    LOCAL_COLOR_TABLE,
+    FINISHED_LOCAL_COLOR_TABLE,
+    IMAGE_DATA_BLOCK,
+    IMAGE_DATA_SUB_BLOCK,
+    LZW_DATA,
+    SKIP_LZW_DATA,
+    FINISHED_LZW_DATA,
+    SKIP_SUB_BLOCKS,
+    SKIP_DATA_THEN_SKIP_SUB_BLOCKS,
+    FINISHED_SKIPPING_DATA
+  };
+
+  LexerTransition<State> ReadGIFHeader(const char* aData);
+  LexerTransition<State> ReadScreenDescriptor(const char* aData);
+  LexerTransition<State> ReadGlobalColorTable(const char* aData,
+                                              size_t aLength);
+  LexerTransition<State> FinishedGlobalColorTable();
+  LexerTransition<State> ReadBlockHeader(const char* aData);
+  LexerTransition<State> ReadExtensionHeader(const char* aData);
+  LexerTransition<State> ReadGraphicControlExtension(const char* aData);
+  LexerTransition<State> ReadApplicationIdentifier(const char* aData);
+  LexerTransition<State> ReadNetscapeExtensionSubBlock(const char* aData);
+  LexerTransition<State> ReadNetscapeExtensionData(const char* aData);
+  LexerTransition<State> ReadImageDescriptor(const char* aData);
+  LexerTransition<State> FinishImageDescriptor(const char* aData);
+  LexerTransition<State> ReadLocalColorTable(const char* aData, size_t aLength);
+  LexerTransition<State> FinishedLocalColorTable();
+  LexerTransition<State> ReadImageDataBlock(const char* aData);
+  LexerTransition<State> ReadImageDataSubBlock(const char* aData);
+  LexerTransition<State> ReadLZWData(const char* aData, size_t aLength);
+  LexerTransition<State> SkipSubBlocks(const char* aData);
+
+  // The StreamingLexer used to manage input. The initial size of the buffer is
+  // chosen as a little larger than the maximum size of any fixed-length data we
+  // have to read for a state. We read variable-length data in unbuffered mode
+  // so the buffer shouldn't have to be resized during decoding.
+  StreamingLexer<State, 16> mLexer;
+
+  uint32_t mOldColor;  // The old value of the transparent pixel
+
+  // The frame number of the currently-decoding frame when we're in the middle
+  // of decoding it, and -1 otherwise.
+  int32_t mCurrentFrameIndex;
+
+  // When we're reading in the global or local color table, this records our
+  // current position - i.e., the offset into which the next byte should be
+  // written.
+  size_t mColorTablePos;
+  uint32_t* mColormap;  // Current colormap to be used in Cairo format
+  uint32_t mColormapSize;
+
+  uint8_t mColorMask;  // Apply this to the pixel to keep within colormap
+  bool mGIFOpen;
+  bool mSawTransparency;
+
+  gif_struct mGIFStruct;
+
+  gfx::SwizzleRowFn mSwizzleFn;  /// Method to unpack color tables from RGB.
+  SurfacePipe mPipe;  /// The SurfacePipe used to write to the output surface.
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsGIFDecoder2_h
diff --git a/image/decoders/nsICODecoder.cpp b/image/decoders/nsICODecoder.cpp
new file mode 100644
index 0000000000..0fbc955855
--- /dev/null
+++ b/image/decoders/nsICODecoder.cpp
@@ -0,0 +1,704 @@
+/* vim:set tw=80 expandtab softtabstop=2 ts=2 sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* This is a Cross-Platform ICO Decoder, which should work everywhere, including
+ * Big-Endian machines like the PowerPC. */
+
+#include "nsICODecoder.h"
+
+#include <stdlib.h>
+
+#include <utility>
+
+#include "RasterImage.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/gfx/Swizzle.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace image {
+
+// Constants.
+static const uint32_t ICOHEADERSIZE = 6;
+static const uint32_t BITMAPINFOSIZE = bmp::InfoHeaderLength::WIN_ICO;
+
+// ----------------------------------------
+// Actual Data Processing
+// ----------------------------------------
+
+// Obtains the number of colors from the bits per pixel
+uint16_t nsICODecoder::GetNumColors() {
+  uint16_t numColors = 0;
+  if (mBPP <= 8) {
+    switch (mBPP) {
+      case 1:
+        numColors = 2;
+        break;
+      case 4:
+        numColors = 16;
+        break;
+      case 8:
+        numColors = 256;
+        break;
+      default:
+        numColors = (uint16_t)-1;
+    }
+  }
+  return numColors;
+}
+
+nsICODecoder::nsICODecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::To(ICOState::HEADER, ICOHEADERSIZE),
+             Transition::TerminateSuccess()),
+      mDirEntry(nullptr),
+      mNumIcons(0),
+      mCurrIcon(0),
+      mBPP(0),
+      mMaskRowSize(0),
+      mCurrMaskLine(0),
+      mIsCursor(false),
+      mHasMaskAlpha(false) {}
+
+nsresult nsICODecoder::FinishInternal() {
+  // We shouldn't be called in error cases
+  MOZ_ASSERT(!HasError(), "Shouldn't call FinishInternal after error!");
+
+  return GetFinalStateFromContainedDecoder();
+}
+
+nsresult nsICODecoder::FinishWithErrorInternal() {
+  // No need to assert !mInFrame here because this condition is enforced by
+  // mContainedDecoder.
+  return GetFinalStateFromContainedDecoder();
+}
+
+nsresult nsICODecoder::GetFinalStateFromContainedDecoder() {
+  if (!mContainedDecoder) {
+    return NS_OK;
+  }
+
+  // Let the contained decoder finish up if necessary.
+  FlushContainedDecoder();
+
+  // Make our state the same as the state of the contained decoder.
+  mDecodeDone = mContainedDecoder->GetDecodeDone();
+  mProgress |= mContainedDecoder->TakeProgress();
+  mInvalidRect.UnionRect(mInvalidRect, mContainedDecoder->TakeInvalidRect());
+  mCurrentFrame = mContainedDecoder->GetCurrentFrameRef();
+
+  // Finalize the frame which we deferred to ensure we could modify the final
+  // result (e.g. to apply the BMP mask).
+  MOZ_ASSERT(!mContainedDecoder->GetFinalizeFrames());
+  if (mCurrentFrame) {
+    mCurrentFrame->FinalizeSurface();
+  }
+
+  // Propagate errors.
+  nsresult rv =
+      HasError() || mContainedDecoder->HasError() ? NS_ERROR_FAILURE : NS_OK;
+
+  MOZ_ASSERT(NS_FAILED(rv) || !mCurrentFrame || mCurrentFrame->IsFinished());
+  return rv;
+}
+
+LexerTransition<ICOState> nsICODecoder::ReadHeader(const char* aData) {
+  // If the third byte is 1, this is an icon. If 2, a cursor.
+  if ((aData[2] != 1) && (aData[2] != 2)) {
+    return Transition::TerminateFailure();
+  }
+  mIsCursor = (aData[2] == 2);
+
+  // The fifth and sixth bytes specify the number of resources in the file.
+  mNumIcons = LittleEndian::readUint16(aData + 4);
+  if (mNumIcons == 0) {
+    return Transition::TerminateSuccess();  // Nothing to do.
+  }
+
+  // Downscale-during-decode can end up decoding different resources in the ICO
+  // file depending on the target size. Since the resources are not necessarily
+  // scaled versions of the same image, some may be transparent and some may not
+  // be. We could be precise about transparency if we decoded the metadata of
+  // every resource, but for now we don't and it's safest to assume that
+  // transparency could be present.
+  PostHasTransparency();
+
+  return Transition::To(ICOState::DIR_ENTRY, ICODIRENTRYSIZE);
+}
+
+size_t nsICODecoder::FirstResourceOffset() const {
+  MOZ_ASSERT(mNumIcons > 0,
+             "Calling FirstResourceOffset before processing header");
+
+  // The first resource starts right after the directory, which starts right
+  // after the ICO header.
+  return ICOHEADERSIZE + mNumIcons * ICODIRENTRYSIZE;
+}
+
+LexerTransition<ICOState> nsICODecoder::ReadDirEntry(const char* aData) {
+  mCurrIcon++;
+
+  // Ensure the resource has an offset past the ICO headers.
+  uint32_t offset = LittleEndian::readUint32(aData + 12);
+  if (offset >= FirstResourceOffset()) {
+    // Read the directory entry.
+    IconDirEntryEx e;
+    e.mWidth = aData[0];
+    e.mHeight = aData[1];
+    e.mColorCount = aData[2];
+    e.mReserved = aData[3];
+    e.mPlanes = LittleEndian::readUint16(aData + 4);
+    e.mBitCount = LittleEndian::readUint16(aData + 6);
+    e.mBytesInRes = LittleEndian::readUint32(aData + 8);
+    e.mImageOffset = offset;
+    e.mSize = OrientedIntSize(e.mWidth, e.mHeight);
+
+    // Only accept entries with sufficient resource data to actually contain
+    // some image data.
+    if (e.mBytesInRes > BITMAPINFOSIZE) {
+      if (e.mWidth == 0 || e.mHeight == 0) {
+        mUnsizedDirEntries.AppendElement(e);
+      } else {
+        mDirEntries.AppendElement(e);
+      }
+    }
+  }
+
+  if (mCurrIcon == mNumIcons) {
+    if (mUnsizedDirEntries.IsEmpty()) {
+      return Transition::To(ICOState::FINISHED_DIR_ENTRY, 0);
+    }
+    return Transition::To(ICOState::ITERATE_UNSIZED_DIR_ENTRY, 0);
+  }
+
+  return Transition::To(ICOState::DIR_ENTRY, ICODIRENTRYSIZE);
+}
+
+LexerTransition<ICOState> nsICODecoder::IterateUnsizedDirEntry() {
+  MOZ_ASSERT(!mUnsizedDirEntries.IsEmpty());
+
+  if (!mDirEntry) {
+    // The first time we are here, there is no entry selected. We must prepare a
+    // new iterator for the contained decoder to advance as it wills. Cloning at
+    // this point ensures it will begin at the end of the dir entries.
+    mReturnIterator = mLexer.Clone(*mIterator, SIZE_MAX);
+    if (mReturnIterator.isNothing()) {
+      // If we cannot read further than this point, then there is no resource
+      // data to read.
+      return Transition::TerminateFailure();
+    }
+  } else {
+    // We have already selected an entry which means a metadata decoder has
+    // finished. Verify the size is valid and if so, add to the discovered
+    // resources.
+    if (mDirEntry->mSize.width > 0 && mDirEntry->mSize.height > 0) {
+      mDirEntries.AppendElement(*mDirEntry);
+    }
+
+    // Remove the entry from the unsized list either way.
+    mDirEntry = nullptr;
+    mUnsizedDirEntries.RemoveElementAt(0);
+
+    // Our iterator is at an unknown point, so reset it to the point that we
+    // saved.
+    mIterator = mLexer.Clone(*mReturnIterator, SIZE_MAX);
+    if (mIterator.isNothing()) {
+      MOZ_ASSERT_UNREACHABLE("Cannot re-clone return iterator");
+      return Transition::TerminateFailure();
+    }
+  }
+
+  // There are no more unsized entries, so we can finally decide which entry to
+  // select for decoding.
+  if (mUnsizedDirEntries.IsEmpty()) {
+    mReturnIterator.reset();
+    return Transition::To(ICOState::FINISHED_DIR_ENTRY, 0);
+  }
+
+  // Move to the resource data to start metadata decoding.
+  mDirEntry = &mUnsizedDirEntries[0];
+  size_t offsetToResource = mDirEntry->mImageOffset - FirstResourceOffset();
+  return Transition::ToUnbuffered(ICOState::FOUND_RESOURCE,
+                                  ICOState::SKIP_TO_RESOURCE, offsetToResource);
+}
+
+LexerTransition<ICOState> nsICODecoder::FinishDirEntry() {
+  MOZ_ASSERT(!mDirEntry);
+
+  if (mDirEntries.IsEmpty()) {
+    return Transition::TerminateFailure();
+  }
+
+  // If an explicit output size was specified, we'll try to select the resource
+  // that matches it best below.
+  const Maybe<OrientedIntSize> desiredSize = ExplicitOutputSize();
+
+  // Determine the biggest resource. We always use the biggest resource for the
+  // intrinsic size, and if we don't have a specific desired size, we select it
+  // as the best resource as well.
+  int32_t bestDelta = INT32_MIN;
+  IconDirEntryEx* biggestEntry = nullptr;
+
+  for (size_t i = 0; i < mDirEntries.Length(); ++i) {
+    IconDirEntryEx& e = mDirEntries[i];
+    mImageMetadata.AddNativeSize(e.mSize);
+
+    if (!biggestEntry ||
+        (e.mBitCount >= biggestEntry->mBitCount &&
+         e.mSize.width * e.mSize.height >=
+             biggestEntry->mSize.width * biggestEntry->mSize.height)) {
+      biggestEntry = &e;
+
+      if (!desiredSize) {
+        mDirEntry = &e;
+      }
+    }
+
+    if (desiredSize) {
+      // Calculate the delta between this resource's size and the desired size,
+      // so we can see if it is better than our current-best option.  In the
+      // case of several equally-good resources, we use the last one. "Better"
+      // in this case is determined by |delta|, a measure of the difference in
+      // size between the entry we've found and the desired size. We will choose
+      // the smallest resource that is greater than or equal to the desired size
+      // (i.e. we assume it's better to downscale a larger icon than to upscale
+      // a smaller one).
+      int32_t delta = std::min(e.mSize.width - desiredSize->width,
+                               e.mSize.height - desiredSize->height);
+      if (!mDirEntry || (e.mBitCount >= mDirEntry->mBitCount &&
+                         ((bestDelta < 0 && delta >= bestDelta) ||
+                          (delta >= 0 && delta <= bestDelta)))) {
+        mDirEntry = &e;
+        bestDelta = delta;
+      }
+    }
+  }
+
+  MOZ_ASSERT(mDirEntry);
+  MOZ_ASSERT(biggestEntry);
+
+  // If this is a cursor, set the hotspot. We use the hotspot from the biggest
+  // resource since we also use that resource for the intrinsic size.
+  if (mIsCursor) {
+    mImageMetadata.SetHotspot(biggestEntry->mXHotspot, biggestEntry->mYHotspot);
+  }
+
+  // We always report the biggest resource's size as the intrinsic size; this
+  // is necessary for downscale-during-decode to work since we won't even
+  // attempt to *upscale* while decoding.
+  PostSize(biggestEntry->mSize.width, biggestEntry->mSize.height);
+  if (HasError()) {
+    return Transition::TerminateFailure();
+  }
+
+  if (IsMetadataDecode()) {
+    return Transition::TerminateSuccess();
+  }
+
+  if (mDirEntry->mSize == OutputSize()) {
+    // If the resource we selected matches the output size perfectly, we don't
+    // need to do any downscaling.
+    MOZ_ASSERT_IF(desiredSize, mDirEntry->mSize == *desiredSize);
+    MOZ_ASSERT_IF(!desiredSize, mDirEntry->mSize == Size());
+  } else if (OutputSize().width < mDirEntry->mSize.width ||
+             OutputSize().height < mDirEntry->mSize.height) {
+    // Create a downscaler if we need to downscale.
+    //
+    // TODO(aosmond): This is the last user of Downscaler. We should switch this
+    // to SurfacePipe as well so we can remove the code from tree.
+    mDownscaler.emplace(OutputSize().ToUnknownSize());
+  }
+
+  size_t offsetToResource = mDirEntry->mImageOffset - FirstResourceOffset();
+  return Transition::ToUnbuffered(ICOState::FOUND_RESOURCE,
+                                  ICOState::SKIP_TO_RESOURCE, offsetToResource);
+}
+
+LexerTransition<ICOState> nsICODecoder::SniffResource(const char* aData) {
+  MOZ_ASSERT(mDirEntry);
+
+  // We have BITMAPINFOSIZE bytes buffered at this point. We know an embedded
+  // BMP will have at least that many bytes by definition. We can also infer
+  // that any valid embedded PNG will contain that many bytes as well because:
+  //    BITMAPINFOSIZE
+  //      <
+  //    signature (8 bytes) +
+  //    IHDR (12 bytes header + 13 bytes data)
+  //    IDAT (12 bytes header)
+
+  // We use the first PNGSIGNATURESIZE bytes to determine whether this resource
+  // is a PNG or a BMP.
+  bool isPNG =
+      !memcmp(aData, nsPNGDecoder::pngSignatureBytes, PNGSIGNATURESIZE);
+  if (isPNG) {
+    if (mDirEntry->mBytesInRes <= BITMAPINFOSIZE) {
+      return Transition::TerminateFailure();
+    }
+
+    // Prepare a new iterator for the contained decoder to advance as it wills.
+    // Cloning at the point ensures it will begin at the resource offset.
+    Maybe<SourceBufferIterator> containedIterator =
+        mLexer.Clone(*mIterator, mDirEntry->mBytesInRes);
+    if (containedIterator.isNothing()) {
+      return Transition::TerminateFailure();
+    }
+
+    // Create a PNG decoder which will do the rest of the work for us.
+    bool metadataDecode = mReturnIterator.isSome();
+    Maybe<OrientedIntSize> expectedSize =
+        metadataDecode ? Nothing() : Some(mDirEntry->mSize);
+    mContainedDecoder = DecoderFactory::CreateDecoderForICOResource(
+        DecoderType::PNG, std::move(containedIterator.ref()), WrapNotNull(this),
+        metadataDecode, expectedSize);
+
+    // Read in the rest of the PNG unbuffered.
+    size_t toRead = mDirEntry->mBytesInRes - BITMAPINFOSIZE;
+    return Transition::ToUnbuffered(ICOState::FINISHED_RESOURCE,
+                                    ICOState::READ_RESOURCE, toRead);
+  }
+
+  // Make sure we have a sane size for the bitmap information header.
+  int32_t bihSize = LittleEndian::readUint32(aData);
+  if (bihSize != static_cast<int32_t>(BITMAPINFOSIZE)) {
+    return Transition::TerminateFailure();
+  }
+
+  // Read in the rest of the bitmap information header.
+  return ReadBIH(aData);
+}
+
+LexerTransition<ICOState> nsICODecoder::ReadResource() {
+  if (!FlushContainedDecoder()) {
+    return Transition::TerminateFailure();
+  }
+
+  return Transition::ContinueUnbuffered(ICOState::READ_RESOURCE);
+}
+
+LexerTransition<ICOState> nsICODecoder::ReadBIH(const char* aData) {
+  MOZ_ASSERT(mDirEntry);
+
+  // Extract the BPP from the BIH header; it should be trusted over the one
+  // we have from the ICO header which is usually set to 0.
+  mBPP = LittleEndian::readUint16(aData + 14);
+
+  // Check to make sure we have valid color settings.
+  uint16_t numColors = GetNumColors();
+  if (numColors == uint16_t(-1)) {
+    return Transition::TerminateFailure();
+  }
+
+  // The color table is present only if BPP is <= 8.
+  MOZ_ASSERT_IF(mBPP > 8, numColors == 0);
+
+  // The ICO format when containing a BMP does not include the 14 byte
+  // bitmap file header. So we create the BMP decoder via the constructor that
+  // tells it to skip this, and pass in the required data (dataOffset) that
+  // would have been present in the header.
+  uint32_t dataOffset =
+      bmp::FILE_HEADER_LENGTH + BITMAPINFOSIZE + 4 * numColors;
+
+  // Prepare a new iterator for the contained decoder to advance as it wills.
+  // Cloning at the point ensures it will begin at the resource offset.
+  Maybe<SourceBufferIterator> containedIterator =
+      mLexer.Clone(*mIterator, mDirEntry->mBytesInRes);
+  if (containedIterator.isNothing()) {
+    return Transition::TerminateFailure();
+  }
+
+  // Create a BMP decoder which will do most of the work for us; the exception
+  // is the AND mask, which isn't present in standalone BMPs.
+  bool metadataDecode = mReturnIterator.isSome();
+  Maybe<OrientedIntSize> expectedSize =
+      metadataDecode ? Nothing() : Some(mDirEntry->mSize);
+  mContainedDecoder = DecoderFactory::CreateDecoderForICOResource(
+      DecoderType::BMP, std::move(containedIterator.ref()), WrapNotNull(this),
+      metadataDecode, expectedSize, Some(dataOffset));
+
+  RefPtr<nsBMPDecoder> bmpDecoder =
+      static_cast<nsBMPDecoder*>(mContainedDecoder.get());
+
+  // Ensure the decoder has parsed at least the BMP's bitmap info header.
+  if (!FlushContainedDecoder()) {
+    return Transition::TerminateFailure();
+  }
+
+  // If this is a metadata decode, FinishResource will any necessary checks.
+  if (mContainedDecoder->IsMetadataDecode()) {
+    return Transition::To(ICOState::FINISHED_RESOURCE, 0);
+  }
+
+  // Do we have an AND mask on this BMP? If so, we need to read it after we read
+  // the BMP data itself.
+  uint32_t bmpDataLength = bmpDecoder->GetCompressedImageSize() + 4 * numColors;
+  bool hasANDMask = (BITMAPINFOSIZE + bmpDataLength) < mDirEntry->mBytesInRes;
+  ICOState afterBMPState =
+      hasANDMask ? ICOState::PREPARE_FOR_MASK : ICOState::FINISHED_RESOURCE;
+
+  // Read in the rest of the BMP unbuffered.
+  return Transition::ToUnbuffered(afterBMPState, ICOState::READ_RESOURCE,
+                                  bmpDataLength);
+}
+
+LexerTransition<ICOState> nsICODecoder::PrepareForMask() {
+  MOZ_ASSERT(mDirEntry);
+  MOZ_ASSERT(mContainedDecoder->GetDecodeDone());
+
+  // We have received all of the data required by the BMP decoder so flushing
+  // here guarantees the decode has finished.
+  if (!FlushContainedDecoder()) {
+    return Transition::TerminateFailure();
+  }
+
+  MOZ_ASSERT(mContainedDecoder->GetDecodeDone());
+
+  RefPtr<nsBMPDecoder> bmpDecoder =
+      static_cast<nsBMPDecoder*>(mContainedDecoder.get());
+
+  uint16_t numColors = GetNumColors();
+  MOZ_ASSERT(numColors != uint16_t(-1));
+
+  // Determine the length of the AND mask.
+  uint32_t bmpLengthWithHeader =
+      BITMAPINFOSIZE + bmpDecoder->GetCompressedImageSize() + 4 * numColors;
+  MOZ_ASSERT(bmpLengthWithHeader < mDirEntry->mBytesInRes);
+  uint32_t maskLength = mDirEntry->mBytesInRes - bmpLengthWithHeader;
+
+  // If the BMP provides its own transparency, we ignore the AND mask.
+  if (bmpDecoder->HasTransparency()) {
+    return Transition::ToUnbuffered(ICOState::FINISHED_RESOURCE,
+                                    ICOState::SKIP_MASK, maskLength);
+  }
+
+  // Compute the row size for the mask.
+  mMaskRowSize = ((mDirEntry->mSize.width + 31) / 32) * 4;  // + 31 to round up
+
+  // If the expected size of the AND mask is larger than its actual size, then
+  // we must have a truncated (and therefore corrupt) AND mask.
+  uint32_t expectedLength = mMaskRowSize * mDirEntry->mSize.height;
+  if (maskLength < expectedLength) {
+    return Transition::TerminateFailure();
+  }
+
+  // If we're downscaling, the mask is the wrong size for the surface we've
+  // produced, so we need to downscale the mask into a temporary buffer and then
+  // combine the mask's alpha values with the color values from the image.
+  if (mDownscaler) {
+    MOZ_ASSERT(bmpDecoder->GetImageDataLength() ==
+               mDownscaler->TargetSize().width *
+                   mDownscaler->TargetSize().height * sizeof(uint32_t));
+    mMaskBuffer = MakeUnique<uint8_t[]>(bmpDecoder->GetImageDataLength());
+    nsresult rv = mDownscaler->BeginFrame(mDirEntry->mSize.ToUnknownSize(),
+                                          Nothing(), mMaskBuffer.get(),
+                                          /* aHasAlpha = */ true,
+                                          /* aFlipVertically = */ true);
+    if (NS_FAILED(rv)) {
+      return Transition::TerminateFailure();
+    }
+  }
+
+  mCurrMaskLine = mDirEntry->mSize.height;
+  return Transition::To(ICOState::READ_MASK_ROW, mMaskRowSize);
+}
+
+LexerTransition<ICOState> nsICODecoder::ReadMaskRow(const char* aData) {
+  MOZ_ASSERT(mDirEntry);
+
+  mCurrMaskLine--;
+
+  uint8_t sawTransparency = 0;
+
+  // Get the mask row we're reading.
+  const uint8_t* mask = reinterpret_cast<const uint8_t*>(aData);
+  const uint8_t* maskRowEnd = mask + mMaskRowSize;
+
+  // Get the corresponding row of the mask buffer (if we're downscaling) or the
+  // decoded image data (if we're not).
+  uint32_t* decoded = nullptr;
+  if (mDownscaler) {
+    // Initialize the row to all white and fully opaque.
+    memset(mDownscaler->RowBuffer(), 0xFF,
+           mDirEntry->mSize.width * sizeof(uint32_t));
+
+    decoded = reinterpret_cast<uint32_t*>(mDownscaler->RowBuffer());
+  } else {
+    RefPtr<nsBMPDecoder> bmpDecoder =
+        static_cast<nsBMPDecoder*>(mContainedDecoder.get());
+    uint32_t* imageData = bmpDecoder->GetImageData();
+    if (!imageData) {
+      return Transition::TerminateFailure();
+    }
+
+    decoded = imageData + mCurrMaskLine * mDirEntry->mSize.width;
+  }
+
+  MOZ_ASSERT(decoded);
+  uint32_t* decodedRowEnd = decoded + mDirEntry->mSize.width;
+
+  // Iterate simultaneously through the AND mask and the image data.
+  while (mask < maskRowEnd) {
+    uint8_t idx = *mask++;
+    sawTransparency |= idx;
+    for (uint8_t bit = 0x80; bit && decoded < decodedRowEnd; bit >>= 1) {
+      // Clear pixel completely for transparency.
+      if (idx & bit) {
+        *decoded = 0;
+      }
+      decoded++;
+    }
+  }
+
+  if (mDownscaler) {
+    mDownscaler->CommitRow();
+  }
+
+  // If any bits are set in sawTransparency, then we know at least one pixel was
+  // transparent.
+  if (sawTransparency) {
+    mHasMaskAlpha = true;
+  }
+
+  if (mCurrMaskLine == 0) {
+    return Transition::To(ICOState::FINISH_MASK, 0);
+  }
+
+  return Transition::To(ICOState::READ_MASK_ROW, mMaskRowSize);
+}
+
+LexerTransition<ICOState> nsICODecoder::FinishMask() {
+  // If we're downscaling, we now have the appropriate alpha values in
+  // mMaskBuffer. We just need to transfer them to the image.
+  if (mDownscaler) {
+    // Retrieve the image data.
+    RefPtr<nsBMPDecoder> bmpDecoder =
+        static_cast<nsBMPDecoder*>(mContainedDecoder.get());
+    uint8_t* imageData = reinterpret_cast<uint8_t*>(bmpDecoder->GetImageData());
+    if (!imageData) {
+      return Transition::TerminateFailure();
+    }
+
+    // Iterate through the alpha values, copying from mask to image.
+    MOZ_ASSERT(mMaskBuffer);
+    MOZ_ASSERT(bmpDecoder->GetImageDataLength() > 0);
+    for (size_t i = 3; i < bmpDecoder->GetImageDataLength(); i += 4) {
+      imageData[i] = mMaskBuffer[i];
+    }
+    int32_t stride = mDownscaler->TargetSize().width * sizeof(uint32_t);
+    DebugOnly<bool> ret =
+        // We know the format is OS_RGBA because we always assume bmp's inside
+        // ico's are transparent.
+        PremultiplyData(imageData, stride, SurfaceFormat::OS_RGBA, imageData,
+                        stride, SurfaceFormat::OS_RGBA,
+                        mDownscaler->TargetSize());
+    MOZ_ASSERT(ret);
+  }
+
+  return Transition::To(ICOState::FINISHED_RESOURCE, 0);
+}
+
+LexerTransition<ICOState> nsICODecoder::FinishResource() {
+  MOZ_ASSERT(mDirEntry);
+
+  // We have received all of the data required by the PNG/BMP decoder so
+  // flushing here guarantees the decode has finished.
+  if (!FlushContainedDecoder()) {
+    return Transition::TerminateFailure();
+  }
+
+  MOZ_ASSERT(mContainedDecoder->GetDecodeDone());
+
+  // If it is a metadata decode, all we were trying to get was the size
+  // information missing from the dir entry.
+  if (mContainedDecoder->IsMetadataDecode()) {
+    if (mContainedDecoder->HasSize()) {
+      mDirEntry->mSize = mContainedDecoder->Size();
+    }
+    return Transition::To(ICOState::ITERATE_UNSIZED_DIR_ENTRY, 0);
+  }
+
+  // Raymond Chen says that 32bpp only are valid PNG ICOs
+  // http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
+  if (!mContainedDecoder->IsValidICOResource()) {
+    return Transition::TerminateFailure();
+  }
+
+  // This size from the resource should match that from the dir entry.
+  MOZ_ASSERT_IF(mContainedDecoder->HasSize(),
+                mContainedDecoder->Size() == mDirEntry->mSize);
+
+  return Transition::TerminateSuccess();
+}
+
+LexerResult nsICODecoder::DoDecode(SourceBufferIterator& aIterator,
+                                   IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(
+      aIterator, aOnResume,
+      [=](ICOState aState, const char* aData, size_t aLength) {
+        switch (aState) {
+          case ICOState::HEADER:
+            return ReadHeader(aData);
+          case ICOState::DIR_ENTRY:
+            return ReadDirEntry(aData);
+          case ICOState::FINISHED_DIR_ENTRY:
+            return FinishDirEntry();
+          case ICOState::ITERATE_UNSIZED_DIR_ENTRY:
+            return IterateUnsizedDirEntry();
+          case ICOState::SKIP_TO_RESOURCE:
+            return Transition::ContinueUnbuffered(ICOState::SKIP_TO_RESOURCE);
+          case ICOState::FOUND_RESOURCE:
+            return Transition::To(ICOState::SNIFF_RESOURCE, BITMAPINFOSIZE);
+          case ICOState::SNIFF_RESOURCE:
+            return SniffResource(aData);
+          case ICOState::READ_RESOURCE:
+            return ReadResource();
+          case ICOState::PREPARE_FOR_MASK:
+            return PrepareForMask();
+          case ICOState::READ_MASK_ROW:
+            return ReadMaskRow(aData);
+          case ICOState::FINISH_MASK:
+            return FinishMask();
+          case ICOState::SKIP_MASK:
+            return Transition::ContinueUnbuffered(ICOState::SKIP_MASK);
+          case ICOState::FINISHED_RESOURCE:
+            return FinishResource();
+          default:
+            MOZ_CRASH("Unknown ICOState");
+        }
+      });
+}
+
+bool nsICODecoder::FlushContainedDecoder() {
+  MOZ_ASSERT(mContainedDecoder);
+
+  bool succeeded = true;
+
+  // If we run out of data, the ICO decoder will get resumed when there's more
+  // data available, as usual, so we don't need the contained decoder to get
+  // resumed too. To avoid that, we provide an IResumable which just does
+  // nothing. All the caller needs to do is flush when there is new data.
+  LexerResult result = mContainedDecoder->Decode();
+  if (result == LexerResult(TerminalState::FAILURE)) {
+    succeeded = false;
+  }
+
+  MOZ_ASSERT(result != LexerResult(Yield::OUTPUT_AVAILABLE),
+             "Unexpected yield");
+
+  // Make our state the same as the state of the contained decoder, and
+  // propagate errors.
+  mProgress |= mContainedDecoder->TakeProgress();
+  mInvalidRect.UnionRect(mInvalidRect, mContainedDecoder->TakeInvalidRect());
+  if (mContainedDecoder->HasError()) {
+    succeeded = false;
+  }
+
+  return succeeded;
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsICODecoder.h b/image/decoders/nsICODecoder.h
new file mode 100644
index 0000000000..4e2665334e
--- /dev/null
+++ b/image/decoders/nsICODecoder.h
@@ -0,0 +1,106 @@
+/* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=2: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsICODecoder_h
+#define mozilla_image_decoders_nsICODecoder_h
+
+#include "StreamingLexer.h"
+#include "Decoder.h"
+#include "Downscaler.h"
+#include "imgFrame.h"
+#include "mozilla/gfx/2D.h"
+#include "nsBMPDecoder.h"
+#include "nsPNGDecoder.h"
+#include "ICOFileHeaders.h"
+
+namespace mozilla {
+namespace image {
+
+class RasterImage;
+
+enum class ICOState {
+  HEADER,
+  DIR_ENTRY,
+  FINISHED_DIR_ENTRY,
+  ITERATE_UNSIZED_DIR_ENTRY,
+  SKIP_TO_RESOURCE,
+  FOUND_RESOURCE,
+  SNIFF_RESOURCE,
+  READ_RESOURCE,
+  PREPARE_FOR_MASK,
+  READ_MASK_ROW,
+  FINISH_MASK,
+  SKIP_MASK,
+  FINISHED_RESOURCE
+};
+
+class nsICODecoder : public Decoder {
+ public:
+  virtual ~nsICODecoder() {}
+
+  /// @return The offset from the beginning of the ICO to the first resource.
+  size_t FirstResourceOffset() const;
+
+  DecoderType GetType() const override { return DecoderType::ICO; }
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+  nsresult FinishInternal() override;
+  nsresult FinishWithErrorInternal() override;
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsICODecoder(RasterImage* aImage);
+
+  // Flushes the contained decoder to read all available data and sets the
+  // appropriate errors. Returns true if there are no errors.
+  bool FlushContainedDecoder();
+
+  // Gets decoder state from the contained decoder so it's visible externally.
+  nsresult GetFinalStateFromContainedDecoder();
+
+  // Obtains the number of colors from the BPP, mBPP must be filled in
+  uint16_t GetNumColors();
+
+  LexerTransition<ICOState> ReadHeader(const char* aData);
+  LexerTransition<ICOState> ReadDirEntry(const char* aData);
+  LexerTransition<ICOState> IterateUnsizedDirEntry();
+  LexerTransition<ICOState> FinishDirEntry();
+  LexerTransition<ICOState> SniffResource(const char* aData);
+  LexerTransition<ICOState> ReadResource();
+  LexerTransition<ICOState> ReadBIH(const char* aData);
+  LexerTransition<ICOState> PrepareForMask();
+  LexerTransition<ICOState> ReadMaskRow(const char* aData);
+  LexerTransition<ICOState> FinishMask();
+  LexerTransition<ICOState> FinishResource();
+
+  struct IconDirEntryEx : public IconDirEntry {
+    OrientedIntSize mSize;
+  };
+
+  StreamingLexer<ICOState, 32> mLexer;  // The lexer.
+  Maybe<Downscaler> mDownscaler;        // The downscaler used for the mask.
+  RefPtr<Decoder> mContainedDecoder;    // Either a BMP or PNG decoder.
+  Maybe<SourceBufferIterator>
+      mReturnIterator;               // Iterator to save return point.
+  UniquePtr<uint8_t[]> mMaskBuffer;  // A temporary buffer for the alpha mask.
+  nsTArray<IconDirEntryEx> mDirEntries;  // Valid dir entries with a size.
+  nsTArray<IconDirEntryEx> mUnsizedDirEntries;  // Dir entries without a size.
+  IconDirEntryEx* mDirEntry;  // The dir entry for the selected resource.
+  uint16_t mNumIcons;         // Stores the number of icons in the ICO file.
+  uint16_t mCurrIcon;  // Stores the current dir entry index we are processing.
+  uint16_t mBPP;       // The BPP of the resource we're decoding.
+  uint32_t
+      mMaskRowSize;  // The size in bytes of each row in the BMP alpha mask.
+  uint32_t mCurrMaskLine;  // The line of the BMP alpha mask we're processing.
+  bool mIsCursor;          // Is this ICO a cursor?
+  bool mHasMaskAlpha;      // Did the BMP alpha mask have any transparency?
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsICODecoder_h
diff --git a/image/decoders/nsIconDecoder.cpp b/image/decoders/nsIconDecoder.cpp
new file mode 100644
index 0000000000..c4ed8b7b06
--- /dev/null
+++ b/image/decoders/nsIconDecoder.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsIconDecoder.h"
+#include "RasterImage.h"
+#include "SurfacePipeFactory.h"
+#include "gfxPlatform.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace image {
+
+static const uint32_t ICON_HEADER_SIZE = 4;
+
+nsIconDecoder::nsIconDecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::To(State::HEADER, ICON_HEADER_SIZE),
+             Transition::TerminateSuccess()),
+      mBytesPerRow()  // set by ReadHeader()
+{
+  // Nothing to do
+}
+
+nsIconDecoder::~nsIconDecoder() {}
+
+LexerResult nsIconDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                    IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(aIterator, aOnResume,
+                    [=](State aState, const char* aData, size_t aLength) {
+                      switch (aState) {
+                        case State::HEADER:
+                          return ReadHeader(aData);
+                        case State::ROW_OF_PIXELS:
+                          return ReadRowOfPixels(aData, aLength);
+                        case State::FINISH:
+                          return Finish();
+                        default:
+                          MOZ_CRASH("Unknown State");
+                      }
+                    });
+}
+
+LexerTransition<nsIconDecoder::State> nsIconDecoder::ReadHeader(
+    const char* aData) {
+  // Grab the width and height.
+  uint8_t width = uint8_t(aData[0]);
+  uint8_t height = uint8_t(aData[1]);
+  SurfaceFormat format = SurfaceFormat(aData[2]);
+  bool transform = bool(aData[3]);
+
+  // FIXME(aosmond): On OSX we get the icon in device space and already
+  // premultiplied, so we can't support the surface flags with icons right now.
+  SurfacePipeFlags pipeFlags = SurfacePipeFlags();
+  if (transform) {
+    if (mCMSMode == CMSMode::All) {
+      mTransform = GetCMSsRGBTransform(format);
+    }
+
+    if (!(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA)) {
+      pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+    }
+  }
+
+  // The input is 32bpp, so we expect 4 bytes of data per pixel.
+  mBytesPerRow = width * 4;
+
+  // Post our size to the superclass.
+  PostSize(width, height);
+
+  // Icons have alpha.
+  PostHasTransparency();
+
+  // If we're doing a metadata decode, we're done.
+  if (IsMetadataDecode()) {
+    return Transition::TerminateSuccess();
+  }
+
+  MOZ_ASSERT(!mImageData, "Already have a buffer allocated?");
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), FullFrame(), format, SurfaceFormat::OS_RGBA,
+      /* aAnimParams */ Nothing(), mTransform, pipeFlags);
+  if (!pipe) {
+    return Transition::TerminateFailure();
+  }
+
+  mPipe = std::move(*pipe);
+
+  MOZ_ASSERT(mImageData, "Should have a buffer now");
+
+  return Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
+}
+
+LexerTransition<nsIconDecoder::State> nsIconDecoder::ReadRowOfPixels(
+    const char* aData, size_t aLength) {
+  MOZ_ASSERT(aLength % 4 == 0, "Rows should contain a multiple of four bytes");
+
+  auto result = mPipe.WriteBuffer(reinterpret_cast<const uint32_t*>(aData));
+  MOZ_ASSERT(result != WriteState::FAILURE);
+
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (invalidRect) {
+    PostInvalidation(invalidRect->mInputSpaceRect,
+                     Some(invalidRect->mOutputSpaceRect));
+  }
+
+  return result == WriteState::FINISHED
+             ? Transition::To(State::FINISH, 0)
+             : Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
+}
+
+LexerTransition<nsIconDecoder::State> nsIconDecoder::Finish() {
+  PostFrameStop();
+  PostDecodeDone();
+
+  return Transition::TerminateSuccess();
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsIconDecoder.h b/image/decoders/nsIconDecoder.h
new file mode 100644
index 0000000000..73bc1b5731
--- /dev/null
+++ b/image/decoders/nsIconDecoder.h
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsIconDecoder_h
+#define mozilla_image_decoders_nsIconDecoder_h
+
+#include "Decoder.h"
+#include "StreamingLexer.h"
+#include "SurfacePipe.h"
+
+namespace mozilla {
+namespace image {
+
+class RasterImage;
+
+////////////////////////////////////////////////////////////////////////////////
+// The icon decoder is a decoder specifically tailored for loading icons
+// from the OS. We've defined our own little format to represent these icons
+// and this decoder takes that format and converts it into 24-bit RGB with
+// alpha channel support. It was modeled a bit off the PPM decoder.
+//
+// The format of the incoming data is as follows:
+//
+// The first two bytes contain the width and the height of the icon.
+// The remaining bytes contain the icon data, 4 bytes per pixel, in
+// ARGB order (platform endianness, A in highest bits, B in lowest
+// bits), row-primary, top-to-bottom, left-to-right, with
+// premultiplied alpha.
+//
+////////////////////////////////////////////////////////////////////////////////
+
+class nsIconDecoder : public Decoder {
+ public:
+  virtual ~nsIconDecoder();
+
+  DecoderType GetType() const override { return DecoderType::ICON; }
+
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsIconDecoder(RasterImage* aImage);
+
+  enum class State { HEADER, ROW_OF_PIXELS, FINISH };
+
+  LexerTransition<State> ReadHeader(const char* aData);
+  LexerTransition<State> ReadRowOfPixels(const char* aData, size_t aLength);
+  LexerTransition<State> Finish();
+
+  StreamingLexer<State> mLexer;
+  SurfacePipe mPipe;
+  uint32_t mBytesPerRow;
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsIconDecoder_h
diff --git a/image/decoders/nsJPEGDecoder.cpp b/image/decoders/nsJPEGDecoder.cpp
new file mode 100644
index 0000000000..61fb1126b6
--- /dev/null
+++ b/image/decoders/nsJPEGDecoder.cpp
@@ -0,0 +1,979 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h"  // Must appear first.
+
+#include "nsJPEGDecoder.h"
+
+#include <cstdint>
+
+#include "imgFrame.h"
+#include "Orientation.h"
+#include "EXIF.h"
+#include "SurfacePipeFactory.h"
+
+#include "nspr.h"
+#include "nsCRT.h"
+#include "gfxColor.h"
+
+#include "jerror.h"
+
+#include "gfxPlatform.h"
+#include "mozilla/EndianUtils.h"
+#include "mozilla/gfx/Types.h"
+#include "mozilla/Telemetry.h"
+
+extern "C" {
+#include "iccjpeg.h"
+}
+
+#if MOZ_BIG_ENDIAN()
+#  define MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB JCS_EXT_XRGB
+#else
+#  define MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB JCS_EXT_BGRX
+#endif
+
+static void cmyk_convert_bgra(uint32_t* aInput, uint32_t* aOutput,
+                              int32_t aWidth);
+
+using mozilla::gfx::SurfaceFormat;
+
+namespace mozilla {
+namespace image {
+
+static mozilla::LazyLogModule sJPEGLog("JPEGDecoder");
+
+static mozilla::LazyLogModule sJPEGDecoderAccountingLog(
+    "JPEGDecoderAccounting");
+
+static qcms_profile* GetICCProfile(struct jpeg_decompress_struct& info) {
+  JOCTET* profilebuf;
+  uint32_t profileLength;
+  qcms_profile* profile = nullptr;
+
+  if (read_icc_profile(&info, &profilebuf, &profileLength)) {
+    profile = qcms_profile_from_memory(profilebuf, profileLength);
+    free(profilebuf);
+  }
+
+  return profile;
+}
+
+METHODDEF(void) init_source(j_decompress_ptr jd);
+METHODDEF(boolean) fill_input_buffer(j_decompress_ptr jd);
+METHODDEF(void) skip_input_data(j_decompress_ptr jd, long num_bytes);
+METHODDEF(void) term_source(j_decompress_ptr jd);
+METHODDEF(void) my_error_exit(j_common_ptr cinfo);
+
+// Normal JFIF markers can't have more bytes than this.
+#define MAX_JPEG_MARKER_LENGTH (((uint32_t)1 << 16) - 1)
+
+nsJPEGDecoder::nsJPEGDecoder(RasterImage* aImage,
+                             Decoder::DecodeStyle aDecodeStyle)
+    : Decoder(aImage),
+      mLexer(Transition::ToUnbuffered(State::FINISHED_JPEG_DATA,
+                                      State::JPEG_DATA, SIZE_MAX),
+             Transition::TerminateSuccess()),
+      mProfile(nullptr),
+      mProfileLength(0),
+      mCMSLine(nullptr),
+      mDecodeStyle(aDecodeStyle) {
+  this->mErr.pub.error_exit = nullptr;
+  this->mErr.pub.emit_message = nullptr;
+  this->mErr.pub.output_message = nullptr;
+  this->mErr.pub.format_message = nullptr;
+  this->mErr.pub.reset_error_mgr = nullptr;
+  this->mErr.pub.msg_code = 0;
+  this->mErr.pub.trace_level = 0;
+  this->mErr.pub.num_warnings = 0;
+  this->mErr.pub.jpeg_message_table = nullptr;
+  this->mErr.pub.last_jpeg_message = 0;
+  this->mErr.pub.addon_message_table = nullptr;
+  this->mErr.pub.first_addon_message = 0;
+  this->mErr.pub.last_addon_message = 0;
+  mState = JPEG_HEADER;
+  mReading = true;
+  mImageData = nullptr;
+
+  mBytesToSkip = 0;
+  memset(&mInfo, 0, sizeof(jpeg_decompress_struct));
+  memset(&mSourceMgr, 0, sizeof(mSourceMgr));
+  mInfo.client_data = (void*)this;
+
+  mSegment = nullptr;
+  mSegmentLen = 0;
+
+  mBackBuffer = nullptr;
+  mBackBufferLen = mBackBufferSize = mBackBufferUnreadLen = 0;
+
+  MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+          ("nsJPEGDecoder::nsJPEGDecoder: Creating JPEG decoder %p", this));
+}
+
+nsJPEGDecoder::~nsJPEGDecoder() {
+  // Step 8: Release JPEG decompression object
+  mInfo.src = nullptr;
+  jpeg_destroy_decompress(&mInfo);
+
+  free(mBackBuffer);
+  mBackBuffer = nullptr;
+
+  delete[] mCMSLine;
+
+  MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+          ("nsJPEGDecoder::~nsJPEGDecoder: Destroying JPEG decoder %p", this));
+}
+
+Maybe<Telemetry::HistogramID> nsJPEGDecoder::SpeedHistogram() const {
+  return Some(Telemetry::IMAGE_DECODE_SPEED_JPEG);
+}
+
+nsresult nsJPEGDecoder::InitInternal() {
+  // We set up the normal JPEG error routines, then override error_exit.
+  mInfo.err = jpeg_std_error(&mErr.pub);
+  //   mInfo.err = jpeg_std_error(&mErr.pub);
+  mErr.pub.error_exit = my_error_exit;
+  // Establish the setjmp return context for my_error_exit to use.
+  if (setjmp(mErr.setjmp_buffer)) {
+    // If we get here, the JPEG code has signaled an error, and initialization
+    // has failed.
+    return NS_ERROR_FAILURE;
+  }
+
+  // Step 1: allocate and initialize JPEG decompression object
+  jpeg_create_decompress(&mInfo);
+  // Set the source manager
+  mInfo.src = &mSourceMgr;
+
+  // Step 2: specify data source (eg, a file)
+
+  // Setup callback functions.
+  mSourceMgr.init_source = init_source;
+  mSourceMgr.fill_input_buffer = fill_input_buffer;
+  mSourceMgr.skip_input_data = skip_input_data;
+  mSourceMgr.resync_to_restart = jpeg_resync_to_restart;
+  mSourceMgr.term_source = term_source;
+
+  // Record app markers for ICC data
+  for (uint32_t m = 0; m < 16; m++) {
+    jpeg_save_markers(&mInfo, JPEG_APP0 + m, 0xFFFF);
+  }
+
+  return NS_OK;
+}
+
+nsresult nsJPEGDecoder::FinishInternal() {
+  // If we're not in any sort of error case, force our state to JPEG_DONE.
+  if ((mState != JPEG_DONE && mState != JPEG_SINK_NON_JPEG_TRAILER) &&
+      (mState != JPEG_ERROR) && !IsMetadataDecode()) {
+    mState = JPEG_DONE;
+  }
+
+  return NS_OK;
+}
+
+LexerResult nsJPEGDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                    IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(aIterator, aOnResume,
+                    [=](State aState, const char* aData, size_t aLength) {
+                      switch (aState) {
+                        case State::JPEG_DATA:
+                          return ReadJPEGData(aData, aLength);
+                        case State::FINISHED_JPEG_DATA:
+                          return FinishedJPEGData();
+                      }
+                      MOZ_CRASH("Unknown State");
+                    });
+}
+
+LexerTransition<nsJPEGDecoder::State> nsJPEGDecoder::ReadJPEGData(
+    const char* aData, size_t aLength) {
+  mSegment = reinterpret_cast<const JOCTET*>(aData);
+  mSegmentLen = aLength;
+
+  // Return here if there is a error within libjpeg.
+  nsresult error_code;
+  // This cast to nsresult makes sense because setjmp() returns whatever we
+  // passed to longjmp(), which was actually an nsresult. These error codes
+  // have been translated from libjpeg error codes, like so:
+  // JERR_OUT_OF_MEMORY => NS_ERROR_OUT_OF_MEMORY
+  // JERR_UNKNOWN_MARKER => NS_ERROR_ILLEGAL_VALUE
+  // JERR_SOF_UNSUPPORTED =>  NS_ERROR_INVALID_CONTENT_ENCODING
+  // <any other error> => NS_ERROR_FAILURE
+  if ((error_code = static_cast<nsresult>(setjmp(mErr.setjmp_buffer))) !=
+      NS_OK) {
+    bool fatal = true;
+    if (error_code == NS_ERROR_FAILURE) {
+      // Error due to corrupt data. Make sure that we don't feed any more data
+      // to libjpeg-turbo.
+      mState = JPEG_SINK_NON_JPEG_TRAILER;
+      MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+              ("} (setjmp returned NS_ERROR_FAILURE)"));
+    } else if (error_code == NS_ERROR_ILLEGAL_VALUE) {
+      // This is a recoverable error. Consume the marker and continue.
+      mInfo.unread_marker = 0;
+      fatal = false;
+    } else if (error_code == NS_ERROR_INVALID_CONTENT_ENCODING) {
+      // The content is encoding frames with a format that libjpeg can't handle.
+      MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+              ("} (setjmp returned NS_ERROR_INVALID_CONTENT_ENCODING)"));
+      // Check to see if we're in the done state, which indicates that we've
+      // already processed the main JPEG data.
+      bool inDoneState = (mState == JPEG_DONE);
+      // Whether we succeed or fail, we shouldn't send any more data.
+      mState = JPEG_SINK_NON_JPEG_TRAILER;
+
+      // If we're in the done state, we exit successfully and attempt to
+      // display the content we've already received. Otherwise, we fallthrough
+      // and treat this as a fatal error.
+      if (inDoneState) {
+        return Transition::TerminateSuccess();
+      }
+    } else {
+      // Error for another reason. (Possibly OOM.)
+      mState = JPEG_ERROR;
+      MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+              ("} (setjmp returned an error)"));
+    }
+
+    if (fatal) {
+      return Transition::TerminateFailure();
+    }
+  }
+
+  MOZ_LOG(sJPEGLog, LogLevel::Debug,
+          ("[this=%p] nsJPEGDecoder::Write -- processing JPEG data\n", this));
+
+  switch (mState) {
+    case JPEG_HEADER: {
+      LOG_SCOPE((mozilla::LogModule*)sJPEGLog,
+                "nsJPEGDecoder::Write -- entering JPEG_HEADER"
+                " case");
+
+      // Step 3: read file parameters with jpeg_read_header()
+      if (jpeg_read_header(&mInfo, TRUE) == JPEG_SUSPENDED) {
+        MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                ("} (JPEG_SUSPENDED)"));
+        return Transition::ContinueUnbuffered(
+            State::JPEG_DATA);  // I/O suspension
+      }
+
+      // Post our size to the superclass
+      EXIFData exif = ReadExifData();
+      PostSize(mInfo.image_width, mInfo.image_height, exif.orientation,
+               exif.resolution);
+      if (HasError()) {
+        // Setting the size led to an error.
+        mState = JPEG_ERROR;
+        return Transition::TerminateFailure();
+      }
+
+      // If we're doing a metadata decode, we're done.
+      if (IsMetadataDecode()) {
+        return Transition::TerminateSuccess();
+      }
+
+      // We're doing a full decode.
+      switch (mInfo.jpeg_color_space) {
+        case JCS_GRAYSCALE:
+        case JCS_RGB:
+        case JCS_YCbCr:
+          // By default, we will output directly to BGRA. If we need to apply
+          // special color transforms, this may change.
+          switch (SurfaceFormat::OS_RGBX) {
+            case SurfaceFormat::B8G8R8X8:
+              mInfo.out_color_space = JCS_EXT_BGRX;
+              break;
+            case SurfaceFormat::X8R8G8B8:
+              mInfo.out_color_space = JCS_EXT_XRGB;
+              break;
+            case SurfaceFormat::R8G8B8X8:
+              mInfo.out_color_space = JCS_EXT_RGBX;
+              break;
+            default:
+              mState = JPEG_ERROR;
+              return Transition::TerminateFailure();
+          }
+          break;
+        case JCS_CMYK:
+        case JCS_YCCK:
+          // libjpeg can convert from YCCK to CMYK, but not to XRGB.
+          mInfo.out_color_space = JCS_CMYK;
+          break;
+        default:
+          mState = JPEG_ERROR;
+          MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                  ("} (unknown colorspace (3))"));
+          return Transition::TerminateFailure();
+      }
+
+      if (mCMSMode != CMSMode::Off) {
+        if ((mInProfile = GetICCProfile(mInfo)) != nullptr &&
+            GetCMSOutputProfile()) {
+          uint32_t profileSpace = qcms_profile_get_color_space(mInProfile);
+
+          qcms_data_type outputType = gfxPlatform::GetCMSOSRGBAType();
+          Maybe<qcms_data_type> inputType;
+          if (profileSpace == icSigRgbData) {
+            // We can always color manage RGB profiles since it happens at the
+            // end of the pipeline.
+            inputType.emplace(outputType);
+          } else if (profileSpace == icSigGrayData &&
+                     mInfo.jpeg_color_space == JCS_GRAYSCALE) {
+            // We can only color manage gray profiles if the original color
+            // space is grayscale. This means we must downscale after color
+            // management since the downscaler assumes BGRA.
+            mInfo.out_color_space = JCS_GRAYSCALE;
+            inputType.emplace(QCMS_DATA_GRAY_8);
+          }
+
+#if 0
+          // We don't currently support CMYK profiles. The following
+          // code dealt with lcms types. Add something like this
+          // back when we gain support for CMYK.
+
+          // Adobe Photoshop writes YCCK/CMYK files with inverted data
+          if (mInfo.out_color_space == JCS_CMYK) {
+            type |= FLAVOR_SH(mInfo.saw_Adobe_marker ? 1 : 0);
+          }
+#endif
+
+          if (inputType) {
+            // Calculate rendering intent.
+            int intent = gfxPlatform::GetRenderingIntent();
+            if (intent == -1) {
+              intent = qcms_profile_get_rendering_intent(mInProfile);
+            }
+
+            // Create the color management transform.
+            mTransform = qcms_transform_create(mInProfile, *inputType,
+                                               GetCMSOutputProfile(),
+                                               outputType, (qcms_intent)intent);
+          }
+        } else if (mCMSMode == CMSMode::All) {
+          mTransform = GetCMSsRGBTransform(SurfaceFormat::OS_RGBX);
+        }
+      }
+
+      // We don't want to use the pipe buffers directly because we don't want
+      // any reads on non-BGRA formatted data.
+      if (mInfo.out_color_space == JCS_GRAYSCALE ||
+          mInfo.out_color_space == JCS_CMYK) {
+        mCMSLine = new (std::nothrow) uint32_t[mInfo.image_width];
+        if (!mCMSLine) {
+          mState = JPEG_ERROR;
+          MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                  ("} (could allocate buffer for color conversion)"));
+          return Transition::TerminateFailure();
+        }
+      }
+
+      // Don't allocate a giant and superfluous memory buffer
+      // when not doing a progressive decode.
+      mInfo.buffered_image =
+          mDecodeStyle == PROGRESSIVE && jpeg_has_multiple_scans(&mInfo);
+
+      /* Used to set up image size so arrays can be allocated */
+      jpeg_calc_output_dimensions(&mInfo);
+
+      // We handle the transform outside the pipeline if we are outputting in
+      // grayscale, because the pipeline wants BGRA pixels, particularly the
+      // downscaling filter, so we can't handle it after downscaling as would
+      // be optimal.
+      qcms_transform* pipeTransform =
+          mInfo.out_color_space != JCS_GRAYSCALE ? mTransform : nullptr;
+
+      Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateReorientSurfacePipe(
+          this, Size(), OutputSize(), SurfaceFormat::OS_RGBX, pipeTransform,
+          GetOrientation());
+      if (!pipe) {
+        mState = JPEG_ERROR;
+        MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                ("} (could not initialize surface pipe)"));
+        return Transition::TerminateFailure();
+      }
+
+      mPipe = std::move(*pipe);
+
+      MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+              ("        JPEGDecoderAccounting: nsJPEGDecoder::"
+               "Write -- created image frame with %ux%u pixels",
+               mInfo.image_width, mInfo.image_height));
+
+      mState = JPEG_START_DECOMPRESS;
+      [[fallthrough]];  // to start decompressing.
+    }
+
+    case JPEG_START_DECOMPRESS: {
+      LOG_SCOPE((mozilla::LogModule*)sJPEGLog,
+                "nsJPEGDecoder::Write -- entering"
+                " JPEG_START_DECOMPRESS case");
+      // Step 4: set parameters for decompression
+
+      // FIXME -- Should reset dct_method and dither mode
+      // for final pass of progressive JPEG
+
+      mInfo.dct_method = JDCT_ISLOW;
+      mInfo.dither_mode = JDITHER_FS;
+      mInfo.do_fancy_upsampling = TRUE;
+      mInfo.enable_2pass_quant = FALSE;
+      mInfo.do_block_smoothing = TRUE;
+
+      // Step 5: Start decompressor
+      if (jpeg_start_decompress(&mInfo) == FALSE) {
+        MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                ("} (I/O suspension after jpeg_start_decompress())"));
+        return Transition::ContinueUnbuffered(
+            State::JPEG_DATA);  // I/O suspension
+      }
+
+      // If this is a progressive JPEG ...
+      mState = mInfo.buffered_image ? JPEG_DECOMPRESS_PROGRESSIVE
+                                    : JPEG_DECOMPRESS_SEQUENTIAL;
+      [[fallthrough]];  // to decompress sequential JPEG.
+    }
+
+    case JPEG_DECOMPRESS_SEQUENTIAL: {
+      if (mState == JPEG_DECOMPRESS_SEQUENTIAL) {
+        LOG_SCOPE((mozilla::LogModule*)sJPEGLog,
+                  "nsJPEGDecoder::Write -- "
+                  "JPEG_DECOMPRESS_SEQUENTIAL case");
+
+        switch (OutputScanlines()) {
+          case WriteState::NEED_MORE_DATA:
+            MOZ_LOG(
+                sJPEGDecoderAccountingLog, LogLevel::Debug,
+                ("} (I/O suspension after OutputScanlines() - SEQUENTIAL)"));
+            return Transition::ContinueUnbuffered(
+                State::JPEG_DATA);  // I/O suspension
+          case WriteState::FINISHED:
+            NS_ASSERTION(mInfo.output_scanline == mInfo.output_height,
+                         "We didn't process all of the data!");
+            mState = JPEG_DONE;
+            break;
+          case WriteState::FAILURE:
+            mState = JPEG_ERROR;
+            MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                    ("} (Error in pipeline from OutputScalines())"));
+            return Transition::TerminateFailure();
+        }
+      }
+      [[fallthrough]];  // to decompress progressive JPEG.
+    }
+
+    case JPEG_DECOMPRESS_PROGRESSIVE: {
+      if (mState == JPEG_DECOMPRESS_PROGRESSIVE) {
+        LOG_SCOPE((mozilla::LogModule*)sJPEGLog,
+                  "nsJPEGDecoder::Write -- JPEG_DECOMPRESS_PROGRESSIVE case");
+        auto AllComponentsSeen = [](jpeg_decompress_struct& mInfo) {
+          bool all_components_seen = true;
+          if (mInfo.coef_bits) {
+            for (int c = 0; c < mInfo.num_components; ++c) {
+              bool current_component_seen = mInfo.coef_bits[c][0] != -1;
+              all_components_seen &= current_component_seen;
+            }
+          }
+          return all_components_seen;
+        };
+        int status;
+        int scan_to_display_first = 0;
+        bool all_components_seen;
+        all_components_seen = AllComponentsSeen(mInfo);
+        if (all_components_seen) {
+          scan_to_display_first = mInfo.input_scan_number;
+        }
+
+        do {
+          status = jpeg_consume_input(&mInfo);
+
+          if (status == JPEG_REACHED_SOS || status == JPEG_REACHED_EOI ||
+              status == JPEG_SUSPENDED) {
+            // record the first scan where all components are present
+            all_components_seen = AllComponentsSeen(mInfo);
+            if (!scan_to_display_first && all_components_seen) {
+              scan_to_display_first = mInfo.input_scan_number;
+            }
+          }
+        } while ((status != JPEG_SUSPENDED) && (status != JPEG_REACHED_EOI));
+
+        if (!all_components_seen) {
+          return Transition::ContinueUnbuffered(
+              State::JPEG_DATA);  // I/O suspension
+        }
+        // make sure we never try to access the non-exsitent scan 0
+        if (!scan_to_display_first) {
+          scan_to_display_first = 1;
+        }
+        while (mState != JPEG_DONE) {
+          if (mInfo.output_scanline == 0) {
+            int scan = mInfo.input_scan_number;
+
+            // if we haven't displayed anything yet (output_scan_number==0)
+            // and we have enough data for a complete scan, force output
+            // of the last full scan,  but only if this last scan has seen
+            // DC data from all components
+            if ((mInfo.output_scan_number == 0) &&
+                (scan > scan_to_display_first) &&
+                (status != JPEG_REACHED_EOI)) {
+              scan--;
+            }
+            MOZ_ASSERT(scan > 0, "scan number to small!");
+            if (!jpeg_start_output(&mInfo, scan)) {
+              MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                      ("} (I/O suspension after jpeg_start_output() -"
+                       " PROGRESSIVE)"));
+              return Transition::ContinueUnbuffered(
+                  State::JPEG_DATA);  // I/O suspension
+            }
+          }
+
+          if (mInfo.output_scanline == 0xffffff) {
+            mInfo.output_scanline = 0;
+          }
+
+          switch (OutputScanlines()) {
+            case WriteState::NEED_MORE_DATA:
+              if (mInfo.output_scanline == 0) {
+                // didn't manage to read any lines - flag so we don't call
+                // jpeg_start_output() multiple times for the same scan
+                mInfo.output_scanline = 0xffffff;
+              }
+              MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                      ("} (I/O suspension after OutputScanlines() - "
+                       "PROGRESSIVE)"));
+              return Transition::ContinueUnbuffered(
+                  State::JPEG_DATA);  // I/O suspension
+            case WriteState::FINISHED:
+              NS_ASSERTION(mInfo.output_scanline == mInfo.output_height,
+                           "We didn't process all of the data!");
+
+              if (!jpeg_finish_output(&mInfo)) {
+                MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                        ("} (I/O suspension after jpeg_finish_output() -"
+                         " PROGRESSIVE)"));
+                return Transition::ContinueUnbuffered(
+                    State::JPEG_DATA);  // I/O suspension
+              }
+
+              if (jpeg_input_complete(&mInfo) &&
+                  (mInfo.input_scan_number == mInfo.output_scan_number)) {
+                mState = JPEG_DONE;
+              } else {
+                mInfo.output_scanline = 0;
+                mPipe.ResetToFirstRow();
+              }
+              break;
+            case WriteState::FAILURE:
+              mState = JPEG_ERROR;
+              MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                      ("} (Error in pipeline from OutputScalines())"));
+              return Transition::TerminateFailure();
+          }
+        }
+      }
+      [[fallthrough]];  // to finish decompressing.
+    }
+
+    case JPEG_DONE: {
+      LOG_SCOPE((mozilla::LogModule*)sJPEGLog,
+                "nsJPEGDecoder::ProcessData -- entering"
+                " JPEG_DONE case");
+
+      // Step 7: Finish decompression
+
+      if (jpeg_finish_decompress(&mInfo) == FALSE) {
+        MOZ_LOG(sJPEGDecoderAccountingLog, LogLevel::Debug,
+                ("} (I/O suspension after jpeg_finish_decompress() - DONE)"));
+        return Transition::ContinueUnbuffered(
+            State::JPEG_DATA);  // I/O suspension
+      }
+
+      // Make sure we don't feed any more data to libjpeg-turbo.
+      mState = JPEG_SINK_NON_JPEG_TRAILER;
+
+      // We're done.
+      return Transition::TerminateSuccess();
+    }
+    case JPEG_SINK_NON_JPEG_TRAILER:
+      MOZ_LOG(sJPEGLog, LogLevel::Debug,
+              ("[this=%p] nsJPEGDecoder::ProcessData -- entering"
+               " JPEG_SINK_NON_JPEG_TRAILER case\n",
+               this));
+
+      MOZ_ASSERT_UNREACHABLE(
+          "Should stop getting data after entering state "
+          "JPEG_SINK_NON_JPEG_TRAILER");
+
+      return Transition::TerminateSuccess();
+
+    case JPEG_ERROR:
+      MOZ_ASSERT_UNREACHABLE(
+          "Should stop getting data after entering state "
+          "JPEG_ERROR");
+
+      return Transition::TerminateFailure();
+  }
+
+  MOZ_ASSERT_UNREACHABLE("Escaped the JPEG decoder state machine");
+  return Transition::TerminateFailure();
+}  // namespace image
+
+LexerTransition<nsJPEGDecoder::State> nsJPEGDecoder::FinishedJPEGData() {
+  // Since we set up an unbuffered read for SIZE_MAX bytes, if we actually read
+  // all that data something is really wrong.
+  MOZ_ASSERT_UNREACHABLE("Read the entire address space?");
+  return Transition::TerminateFailure();
+}
+
+EXIFData nsJPEGDecoder::ReadExifData() const {
+  jpeg_saved_marker_ptr marker;
+
+  // Locate the APP1 marker, where EXIF data is stored, in the marker list.
+  for (marker = mInfo.marker_list; marker != nullptr; marker = marker->next) {
+    if (marker->marker == JPEG_APP0 + 1) {
+      break;
+    }
+  }
+
+  // If we're at the end of the list, there's no EXIF data.
+  if (!marker) {
+    return EXIFData();
+  }
+
+  return EXIFParser::Parse(marker->data,
+                           static_cast<uint32_t>(marker->data_length),
+                           gfx::IntSize(mInfo.image_width, mInfo.image_height));
+}
+
+void nsJPEGDecoder::NotifyDone() {
+  PostFrameStop(Opacity::FULLY_OPAQUE);
+  PostDecodeDone();
+}
+
+WriteState nsJPEGDecoder::OutputScanlines() {
+  auto result = mPipe.WritePixelBlocks<uint32_t>(
+      [&](uint32_t* aPixelBlock, int32_t aBlockSize) {
+        JSAMPROW sampleRow = (JSAMPROW)(mCMSLine ? mCMSLine : aPixelBlock);
+        if (jpeg_read_scanlines(&mInfo, &sampleRow, 1) != 1) {
+          return MakeTuple(/* aWritten */ 0, Some(WriteState::NEED_MORE_DATA));
+        }
+
+        switch (mInfo.out_color_space) {
+          default:
+            // Already outputted directly to aPixelBlock as BGRA.
+            MOZ_ASSERT(!mCMSLine);
+            break;
+          case JCS_GRAYSCALE:
+            // The transform here does both color management, and converts the
+            // pixels from grayscale to BGRA. This is why we do it here, instead
+            // of using ColorManagementFilter in the SurfacePipe, because the
+            // other filters (e.g. DownscalingFilter) require BGRA pixels.
+            MOZ_ASSERT(mCMSLine);
+            qcms_transform_data(mTransform, mCMSLine, aPixelBlock,
+                                mInfo.output_width);
+            break;
+          case JCS_CMYK:
+            // Convert from CMYK to BGRA
+            MOZ_ASSERT(mCMSLine);
+            cmyk_convert_bgra(mCMSLine, aPixelBlock, aBlockSize);
+            break;
+        }
+
+        return MakeTuple(aBlockSize, Maybe<WriteState>());
+      });
+
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (invalidRect) {
+    PostInvalidation(invalidRect->mInputSpaceRect,
+                     Some(invalidRect->mOutputSpaceRect));
+  }
+
+  return result;
+}
+
+// Override the standard error method in the IJG JPEG decoder code.
+METHODDEF(void)
+my_error_exit(j_common_ptr cinfo) {
+  decoder_error_mgr* err = (decoder_error_mgr*)cinfo->err;
+
+  // Convert error to a browser error code
+  nsresult error_code;
+  switch (err->pub.msg_code) {
+    case JERR_OUT_OF_MEMORY:
+      error_code = NS_ERROR_OUT_OF_MEMORY;
+      break;
+    case JERR_UNKNOWN_MARKER:
+      error_code = NS_ERROR_ILLEGAL_VALUE;
+      break;
+    case JERR_SOF_UNSUPPORTED:
+      error_code = NS_ERROR_INVALID_CONTENT_ENCODING;
+      break;
+    default:
+      error_code = NS_ERROR_FAILURE;
+  }
+
+#ifdef DEBUG
+  char buffer[JMSG_LENGTH_MAX];
+
+  // Create the message
+  (*err->pub.format_message)(cinfo, buffer);
+
+  fprintf(stderr, "JPEG decoding error:\n%s\n", buffer);
+#endif
+
+  // Return control to the setjmp point.  We pass an nsresult masquerading as
+  // an int, which works because the setjmp() caller casts it back.
+  longjmp(err->setjmp_buffer, static_cast<int>(error_code));
+}
+
+/*******************************************************************************
+ * This is the callback routine from the IJG JPEG library used to supply new
+ * data to the decompressor when its input buffer is exhausted.  It juggles
+ * multiple buffers in an attempt to avoid unnecessary copying of input data.
+ *
+ * (A simpler scheme is possible: It's much easier to use only a single
+ * buffer; when fill_input_buffer() is called, move any unconsumed data
+ * (beyond the current pointer/count) down to the beginning of this buffer and
+ * then load new data into the remaining buffer space.  This approach requires
+ * a little more data copying but is far easier to get right.)
+ *
+ * At any one time, the JPEG decompressor is either reading from the necko
+ * input buffer, which is volatile across top-level calls to the IJG library,
+ * or the "backtrack" buffer.  The backtrack buffer contains the remaining
+ * unconsumed data from the necko buffer after parsing was suspended due
+ * to insufficient data in some previous call to the IJG library.
+ *
+ * When suspending, the decompressor will back up to a convenient restart
+ * point (typically the start of the current MCU). The variables
+ * next_input_byte & bytes_in_buffer indicate where the restart point will be
+ * if the current call returns FALSE.  Data beyond this point must be
+ * rescanned after resumption, so it must be preserved in case the decompressor
+ * decides to backtrack.
+ *
+ * Returns:
+ *  TRUE if additional data is available, FALSE if no data present and
+ *   the JPEG library should therefore suspend processing of input stream
+ ******************************************************************************/
+
+/******************************************************************************/
+/* data source manager method                                                 */
+/******************************************************************************/
+
+/******************************************************************************/
+/* data source manager method
+        Initialize source.  This is called by jpeg_read_header() before any
+        data is actually read.  May leave
+        bytes_in_buffer set to 0 (in which case a fill_input_buffer() call
+        will occur immediately).
+*/
+METHODDEF(void)
+init_source(j_decompress_ptr jd) {}
+
+/******************************************************************************/
+/* data source manager method
+        Skip num_bytes worth of data.  The buffer pointer and count should
+        be advanced over num_bytes input bytes, refilling the buffer as
+        needed.  This is used to skip over a potentially large amount of
+        uninteresting data (such as an APPn marker).  In some applications
+        it may be possible to optimize away the reading of the skipped data,
+        but it's not clear that being smart is worth much trouble; large
+        skips are uncommon.  bytes_in_buffer may be zero on return.
+        A zero or negative skip count should be treated as a no-op.
+*/
+METHODDEF(void)
+skip_input_data(j_decompress_ptr jd, long num_bytes) {
+  struct jpeg_source_mgr* src = jd->src;
+  nsJPEGDecoder* decoder = (nsJPEGDecoder*)(jd->client_data);
+
+  if (num_bytes > (long)src->bytes_in_buffer) {
+    // Can't skip it all right now until we get more data from
+    // network stream. Set things up so that fill_input_buffer
+    // will skip remaining amount.
+    decoder->mBytesToSkip = (size_t)num_bytes - src->bytes_in_buffer;
+    src->next_input_byte += src->bytes_in_buffer;
+    src->bytes_in_buffer = 0;
+
+  } else {
+    // Simple case. Just advance buffer pointer
+
+    src->bytes_in_buffer -= (size_t)num_bytes;
+    src->next_input_byte += num_bytes;
+  }
+}
+
+/******************************************************************************/
+/* data source manager method
+        This is called whenever bytes_in_buffer has reached zero and more
+        data is wanted.  In typical applications, it should read fresh data
+        into the buffer (ignoring the current state of next_input_byte and
+        bytes_in_buffer), reset the pointer & count to the start of the
+        buffer, and return TRUE indicating that the buffer has been reloaded.
+        It is not necessary to fill the buffer entirely, only to obtain at
+        least one more byte.  bytes_in_buffer MUST be set to a positive value
+        if TRUE is returned.  A FALSE return should only be used when I/O
+        suspension is desired.
+*/
+METHODDEF(boolean)
+fill_input_buffer(j_decompress_ptr jd) {
+  struct jpeg_source_mgr* src = jd->src;
+  nsJPEGDecoder* decoder = (nsJPEGDecoder*)(jd->client_data);
+
+  if (decoder->mReading) {
+    const JOCTET* new_buffer = decoder->mSegment;
+    uint32_t new_buflen = decoder->mSegmentLen;
+
+    if (!new_buffer || new_buflen == 0) {
+      return false;  // suspend
+    }
+
+    decoder->mSegmentLen = 0;
+
+    if (decoder->mBytesToSkip) {
+      if (decoder->mBytesToSkip < new_buflen) {
+        // All done skipping bytes; Return what's left.
+        new_buffer += decoder->mBytesToSkip;
+        new_buflen -= decoder->mBytesToSkip;
+        decoder->mBytesToSkip = 0;
+      } else {
+        // Still need to skip some more data in the future
+        decoder->mBytesToSkip -= (size_t)new_buflen;
+        return false;  // suspend
+      }
+    }
+
+    decoder->mBackBufferUnreadLen = src->bytes_in_buffer;
+
+    src->next_input_byte = new_buffer;
+    src->bytes_in_buffer = (size_t)new_buflen;
+    decoder->mReading = false;
+
+    return true;
+  }
+
+  if (src->next_input_byte != decoder->mSegment) {
+    // Backtrack data has been permanently consumed.
+    decoder->mBackBufferUnreadLen = 0;
+    decoder->mBackBufferLen = 0;
+  }
+
+  // Save remainder of netlib buffer in backtrack buffer
+  const uint32_t new_backtrack_buflen =
+      src->bytes_in_buffer + decoder->mBackBufferLen;
+
+  // Make sure backtrack buffer is big enough to hold new data.
+  if (decoder->mBackBufferSize < new_backtrack_buflen) {
+    // Check for malformed MARKER segment lengths, before allocating space
+    // for it
+    if (new_backtrack_buflen > MAX_JPEG_MARKER_LENGTH) {
+      my_error_exit((j_common_ptr)(&decoder->mInfo));
+    }
+
+    // Round up to multiple of 256 bytes.
+    const size_t roundup_buflen = ((new_backtrack_buflen + 255) >> 8) << 8;
+    JOCTET* buf = (JOCTET*)realloc(decoder->mBackBuffer, roundup_buflen);
+    // Check for OOM
+    if (!buf) {
+      decoder->mInfo.err->msg_code = JERR_OUT_OF_MEMORY;
+      my_error_exit((j_common_ptr)(&decoder->mInfo));
+    }
+    decoder->mBackBuffer = buf;
+    decoder->mBackBufferSize = roundup_buflen;
+  }
+
+  // Ensure we actually have a backtrack buffer. Without it, then we know that
+  // there is no data to copy and bytes_in_buffer is already zero.
+  if (decoder->mBackBuffer) {
+    // Copy remainder of netlib segment into backtrack buffer.
+    memmove(decoder->mBackBuffer + decoder->mBackBufferLen,
+            src->next_input_byte, src->bytes_in_buffer);
+  } else {
+    MOZ_ASSERT(src->bytes_in_buffer == 0);
+    MOZ_ASSERT(decoder->mBackBufferLen == 0);
+    MOZ_ASSERT(decoder->mBackBufferUnreadLen == 0);
+  }
+
+  // Point to start of data to be rescanned.
+  src->next_input_byte = decoder->mBackBuffer + decoder->mBackBufferLen -
+                         decoder->mBackBufferUnreadLen;
+  src->bytes_in_buffer += decoder->mBackBufferUnreadLen;
+  decoder->mBackBufferLen = (size_t)new_backtrack_buflen;
+  decoder->mReading = true;
+
+  return false;
+}
+
+/******************************************************************************/
+/* data source manager method */
+/*
+ * Terminate source --- called by jpeg_finish_decompress() after all
+ * data has been read to clean up JPEG source manager. NOT called by
+ * jpeg_abort() or jpeg_destroy().
+ */
+METHODDEF(void)
+term_source(j_decompress_ptr jd) {
+  nsJPEGDecoder* decoder = (nsJPEGDecoder*)(jd->client_data);
+
+  // This function shouldn't be called if we ran into an error we didn't
+  // recover from.
+  MOZ_ASSERT(decoder->mState != JPEG_ERROR,
+             "Calling term_source on a JPEG with mState == JPEG_ERROR!");
+
+  // Notify using a helper method to get around protectedness issues.
+  decoder->NotifyDone();
+}
+
+}  // namespace image
+}  // namespace mozilla
+
+///*************** Inverted CMYK -> RGB conversion *************************
+/// Input is (Inverted) CMYK stored as 4 bytes per pixel.
+/// Output is RGB stored as 3 bytes per pixel.
+/// @param aInput Points to row buffer containing the CMYK bytes for each pixel
+///               in the row.
+/// @param aOutput Points to row buffer to write BGRA to.
+/// @param aWidth Number of pixels in the row.
+static void cmyk_convert_bgra(uint32_t* aInput, uint32_t* aOutput,
+                              int32_t aWidth) {
+  uint8_t* input = reinterpret_cast<uint8_t*>(aInput);
+
+  for (int32_t i = 0; i < aWidth; ++i) {
+    // Source is 'Inverted CMYK', output is RGB.
+    // See: http://www.easyrgb.com/math.php?MATH=M12#text12
+    // Or:  http://www.ilkeratalay.com/colorspacesfaq.php#rgb
+
+    // From CMYK to CMY
+    // C = ( C * ( 1 - K ) + K )
+    // M = ( M * ( 1 - K ) + K )
+    // Y = ( Y * ( 1 - K ) + K )
+
+    // From Inverted CMYK to CMY is thus:
+    // C = ( (1-iC) * (1 - (1-iK)) + (1-iK) ) => 1 - iC*iK
+    // Same for M and Y
+
+    // Convert from CMY (0..1) to RGB (0..1)
+    // R = 1 - C => 1 - (1 - iC*iK) => iC*iK
+    // G = 1 - M => 1 - (1 - iM*iK) => iM*iK
+    // B = 1 - Y => 1 - (1 - iY*iK) => iY*iK
+
+    // Convert from Inverted CMYK (0..255) to RGB (0..255)
+    const uint32_t iC = input[0];
+    const uint32_t iM = input[1];
+    const uint32_t iY = input[2];
+    const uint32_t iK = input[3];
+
+    const uint8_t r = iC * iK / 255;
+    const uint8_t g = iM * iK / 255;
+    const uint8_t b = iY * iK / 255;
+
+    *aOutput++ = (0xFF << mozilla::gfx::SurfaceFormatBit::OS_A) |
+                 (r << mozilla::gfx::SurfaceFormatBit::OS_R) |
+                 (g << mozilla::gfx::SurfaceFormatBit::OS_G) |
+                 (b << mozilla::gfx::SurfaceFormatBit::OS_B);
+    input += 4;
+  }
+}
diff --git a/image/decoders/nsJPEGDecoder.h b/image/decoders/nsJPEGDecoder.h
new file mode 100644
index 0000000000..9e21afc6a2
--- /dev/null
+++ b/image/decoders/nsJPEGDecoder.h
@@ -0,0 +1,112 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsJPEGDecoder_h
+#define mozilla_image_decoders_nsJPEGDecoder_h
+
+#include "RasterImage.h"
+#include "SurfacePipe.h"
+#include "EXIF.h"
+
+// On Windows systems, RasterImage.h brings in 'windows.h', which defines INT32.
+// But the jpeg decoder has its own definition of INT32. To avoid build issues,
+// we need to undefine the version from 'windows.h'.
+#undef INT32
+
+#include "Decoder.h"
+
+extern "C" {
+#include "jpeglib.h"
+}
+
+#include <setjmp.h>
+
+namespace mozilla::image {
+
+typedef struct {
+  struct jpeg_error_mgr pub;  // "public" fields for IJG library
+  jmp_buf setjmp_buffer;      // For handling catastropic errors
+} decoder_error_mgr;
+
+typedef enum {
+  JPEG_HEADER,  // Reading JFIF headers
+  JPEG_START_DECOMPRESS,
+  JPEG_DECOMPRESS_PROGRESSIVE,  // Output progressive pixels
+  JPEG_DECOMPRESS_SEQUENTIAL,   // Output sequential pixels
+  JPEG_DONE,
+  JPEG_SINK_NON_JPEG_TRAILER,  // Some image files have a
+                               // non-JPEG trailer
+  JPEG_ERROR
+} jstate;
+
+class RasterImage;
+struct Orientation;
+
+class nsJPEGDecoder : public Decoder {
+ public:
+  virtual ~nsJPEGDecoder();
+
+  DecoderType GetType() const override { return DecoderType::JPEG; }
+
+  void NotifyDone();
+
+ protected:
+  nsresult InitInternal() override;
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+  nsresult FinishInternal() override;
+
+  Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
+
+ protected:
+  EXIFData ReadExifData() const;
+  WriteState OutputScanlines();
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  nsJPEGDecoder(RasterImage* aImage, Decoder::DecodeStyle aDecodeStyle);
+
+  enum class State { JPEG_DATA, FINISHED_JPEG_DATA };
+
+  void FinishRow(uint32_t aLastSourceRow);
+  LexerTransition<State> ReadJPEGData(const char* aData, size_t aLength);
+  LexerTransition<State> FinishedJPEGData();
+
+  StreamingLexer<State> mLexer;
+
+ public:
+  struct jpeg_decompress_struct mInfo;
+  struct jpeg_source_mgr mSourceMgr;
+  decoder_error_mgr mErr;
+  jstate mState;
+
+  uint32_t mBytesToSkip;
+
+  const JOCTET* mSegment;  // The current segment we are decoding from
+  uint32_t mSegmentLen;    // amount of data in mSegment
+
+  JOCTET* mBackBuffer;
+  uint32_t mBackBufferLen;   // Offset of end of active backtrack data
+  uint32_t mBackBufferSize;  // size in bytes what mBackBuffer was created with
+  uint32_t mBackBufferUnreadLen;  // amount of data currently in mBackBuffer
+
+  JOCTET* mProfile;
+  uint32_t mProfileLength;
+
+  uint32_t* mCMSLine;
+
+  bool mReading;
+
+  const Decoder::DecodeStyle mDecodeStyle;
+
+  SurfacePipe mPipe;
+};
+
+}  // namespace mozilla::image
+
+#endif  // mozilla_image_decoders_nsJPEGDecoder_h
diff --git a/image/decoders/nsJXLDecoder.cpp b/image/decoders/nsJXLDecoder.cpp
new file mode 100644
index 0000000000..145fd94543
--- /dev/null
+++ b/image/decoders/nsJXLDecoder.cpp
@@ -0,0 +1,163 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h"  // Must appear first
+#include "gfxPlatform.h"
+#include "jxl/codestream_header.h"
+#include "jxl/decode_cxx.h"
+#include "jxl/types.h"
+#include "mozilla/TelemetryHistogramEnums.h"
+#include "mozilla/gfx/Point.h"
+#include "nsJXLDecoder.h"
+
+#include "RasterImage.h"
+#include "SurfacePipeFactory.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla::image {
+
+#define JXL_TRY(expr)                        \
+  do {                                       \
+    JxlDecoderStatus status = (expr);        \
+    if (status != JXL_DEC_SUCCESS) {         \
+      return Transition::TerminateFailure(); \
+    }                                        \
+  } while (0);
+
+#define JXL_TRY_BOOL(expr)                   \
+  do {                                       \
+    bool succeeded = (expr);                 \
+    if (!succeeded) {                        \
+      return Transition::TerminateFailure(); \
+    }                                        \
+  } while (0);
+
+static LazyLogModule sJXLLog("JXLDecoder");
+
+nsJXLDecoder::nsJXLDecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::ToUnbuffered(State::FINISHED_JXL_DATA, State::JXL_DATA,
+                                      SIZE_MAX),
+             Transition::TerminateSuccess()),
+      mDecoder(JxlDecoderMake(nullptr)),
+      mParallelRunner(
+          JxlThreadParallelRunnerMake(nullptr, PreferredThreadCount())) {
+  JxlDecoderSubscribeEvents(mDecoder.get(),
+                            JXL_DEC_BASIC_INFO | JXL_DEC_FULL_IMAGE);
+  JxlDecoderSetParallelRunner(mDecoder.get(), JxlThreadParallelRunner,
+                              mParallelRunner.get());
+
+  MOZ_LOG(sJXLLog, LogLevel::Debug,
+          ("[this=%p] nsJXLDecoder::nsJXLDecoder", this));
+}
+
+nsJXLDecoder::~nsJXLDecoder() {
+  MOZ_LOG(sJXLLog, LogLevel::Debug,
+          ("[this=%p] nsJXLDecoder::~nsJXLDecoder", this));
+}
+
+size_t nsJXLDecoder::PreferredThreadCount() {
+  if (IsMetadataDecode()) {
+    return 0;  // no additional worker thread
+  }
+  return JxlThreadParallelRunnerDefaultNumWorkerThreads();
+}
+
+LexerResult nsJXLDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                   IResumable* aOnResume) {
+  // return LexerResult(TerminalState::FAILURE);
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(aIterator, aOnResume,
+                    [=](State aState, const char* aData, size_t aLength) {
+                      switch (aState) {
+                        case State::JXL_DATA:
+                          return ReadJXLData(aData, aLength);
+                        case State::FINISHED_JXL_DATA:
+                          return FinishedJXLData();
+                      }
+                      MOZ_CRASH("Unknown State");
+                    });
+};
+
+LexerTransition<nsJXLDecoder::State> nsJXLDecoder::ReadJXLData(
+    const char* aData, size_t aLength) {
+  const uint8_t* input = (const uint8_t*)aData;
+  size_t length = aLength;
+  if (mBuffer.length() != 0) {
+    JXL_TRY_BOOL(mBuffer.append(aData, aLength));
+    input = mBuffer.begin();
+    length = mBuffer.length();
+  }
+  JXL_TRY(JxlDecoderSetInput(mDecoder.get(), input, length));
+
+  while (true) {
+    JxlDecoderStatus status = JxlDecoderProcessInput(mDecoder.get());
+    switch (status) {
+      case JXL_DEC_ERROR:
+      default:
+        return Transition::TerminateFailure();
+
+      case JXL_DEC_NEED_MORE_INPUT: {
+        size_t remaining = JxlDecoderReleaseInput(mDecoder.get());
+        mBuffer.clear();
+        JXL_TRY_BOOL(mBuffer.append(aData + aLength - remaining, remaining));
+        return Transition::ContinueUnbuffered(State::JXL_DATA);
+      }
+
+      case JXL_DEC_BASIC_INFO: {
+        JXL_TRY(JxlDecoderGetBasicInfo(mDecoder.get(), &mInfo));
+        PostSize(mInfo.xsize, mInfo.ysize);
+        if (mInfo.alpha_bits > 0) {
+          PostHasTransparency();
+        }
+        if (IsMetadataDecode()) {
+          return Transition::TerminateSuccess();
+        }
+        break;
+      }
+
+      case JXL_DEC_NEED_IMAGE_OUT_BUFFER: {
+        size_t size = 0;
+        JxlPixelFormat format{4, JXL_TYPE_UINT8, JXL_LITTLE_ENDIAN, 0};
+        JXL_TRY(JxlDecoderImageOutBufferSize(mDecoder.get(), &format, &size));
+
+        mOutBuffer.clear();
+        JXL_TRY_BOOL(mOutBuffer.growBy(size));
+        JXL_TRY(JxlDecoderSetImageOutBuffer(mDecoder.get(), &format,
+                                            mOutBuffer.begin(), size));
+        break;
+      }
+
+      case JXL_DEC_FULL_IMAGE: {
+        OrientedIntSize size(mInfo.xsize, mInfo.ysize);
+        Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+            this, size, OutputSize(), FullFrame(), SurfaceFormat::R8G8B8A8,
+            SurfaceFormat::OS_RGBA, Nothing(), nullptr, SurfacePipeFlags());
+        for (uint8_t* rowPtr = mOutBuffer.begin(); rowPtr < mOutBuffer.end();
+             rowPtr += mInfo.xsize * 4) {
+          pipe->WriteBuffer(reinterpret_cast<uint32_t*>(rowPtr));
+        }
+
+        if (Maybe<SurfaceInvalidRect> invalidRect = pipe->TakeInvalidRect()) {
+          PostInvalidation(invalidRect->mInputSpaceRect,
+                           Some(invalidRect->mOutputSpaceRect));
+        }
+        PostFrameStop();
+        PostDecodeDone();
+        return Transition::TerminateSuccess();
+      }
+    }
+  }
+}
+
+LexerTransition<nsJXLDecoder::State> nsJXLDecoder::FinishedJXLData() {
+  MOZ_ASSERT_UNREACHABLE("Read the entire address space?");
+  return Transition::TerminateFailure();
+}
+
+}  // namespace mozilla::image
diff --git a/image/decoders/nsJXLDecoder.h b/image/decoders/nsJXLDecoder.h
new file mode 100644
index 0000000000..6cde7456ca
--- /dev/null
+++ b/image/decoders/nsJXLDecoder.h
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsJXLDecoder_h
+#define mozilla_image_decoders_nsJXLDecoder_h
+
+#include "Decoder.h"
+#include "mp4parse.h"
+#include "SurfacePipe.h"
+
+#include "jxl/decode_cxx.h"
+#include "jxl/thread_parallel_runner_cxx.h"
+
+#include "mozilla/Telemetry.h"
+
+namespace mozilla::image {
+class RasterImage;
+
+class nsJXLDecoder final : public Decoder {
+ public:
+  virtual ~nsJXLDecoder();
+
+  DecoderType GetType() const override { return DecoderType::JXL; }
+
+ protected:
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsJXLDecoder(RasterImage* aImage);
+
+  size_t PreferredThreadCount();
+
+  enum class State { JXL_DATA, FINISHED_JXL_DATA };
+
+  LexerTransition<State> ReadJXLData(const char* aData, size_t aLength);
+  LexerTransition<State> FinishedJXLData();
+
+  StreamingLexer<State> mLexer;
+  JxlDecoderPtr mDecoder;
+  JxlThreadParallelRunnerPtr mParallelRunner;
+  Vector<uint8_t> mBuffer;
+  Vector<uint8_t> mOutBuffer;
+  JxlBasicInfo mInfo{};
+};
+
+}  // namespace mozilla::image
+
+#endif  // mozilla_image_decoders_nsJXLDecoder_h
diff --git a/image/decoders/nsPNGDecoder.cpp b/image/decoders/nsPNGDecoder.cpp
new file mode 100644
index 0000000000..afc2762515
--- /dev/null
+++ b/image/decoders/nsPNGDecoder.cpp
@@ -0,0 +1,1035 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h"  // Must appear first
+#include "nsPNGDecoder.h"
+
+#include <algorithm>
+#include <cstdint>
+
+#include "gfxColor.h"
+#include "gfxPlatform.h"
+#include "imgFrame.h"
+#include "nsColor.h"
+#include "nsRect.h"
+#include "nspr.h"
+#include "png.h"
+
+#include "RasterImage.h"
+#include "SurfaceCache.h"
+#include "SurfacePipeFactory.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Telemetry.h"
+
+using namespace mozilla::gfx;
+
+using std::min;
+
+namespace mozilla {
+namespace image {
+
+static LazyLogModule sPNGLog("PNGDecoder");
+static LazyLogModule sPNGDecoderAccountingLog("PNGDecoderAccounting");
+
+// limit image dimensions (bug #251381, #591822, #967656, and #1283961)
+#ifndef MOZ_PNG_MAX_WIDTH
+#  define MOZ_PNG_MAX_WIDTH 0x7fffffff  // Unlimited
+#endif
+#ifndef MOZ_PNG_MAX_HEIGHT
+#  define MOZ_PNG_MAX_HEIGHT 0x7fffffff  // Unlimited
+#endif
+
+/* Controls the maximum chunk size configuration for libpng. We set this to a
+ * very large number, 256MB specifically. */
+static constexpr png_alloc_size_t kPngMaxChunkSize = 0x10000000;
+
+nsPNGDecoder::AnimFrameInfo::AnimFrameInfo()
+    : mDispose(DisposalMethod::KEEP), mBlend(BlendMethod::OVER), mTimeout(0) {}
+
+#ifdef PNG_APNG_SUPPORTED
+
+int32_t GetNextFrameDelay(png_structp aPNG, png_infop aInfo) {
+  // Delay, in seconds, is delayNum / delayDen.
+  png_uint_16 delayNum = png_get_next_frame_delay_num(aPNG, aInfo);
+  png_uint_16 delayDen = png_get_next_frame_delay_den(aPNG, aInfo);
+
+  if (delayNum == 0) {
+    return 0;  // SetFrameTimeout() will set to a minimum.
+  }
+
+  if (delayDen == 0) {
+    delayDen = 100;  // So says the APNG spec.
+  }
+
+  // Need to cast delay_num to float to have a proper division and
+  // the result to int to avoid a compiler warning.
+  return static_cast<int32_t>(static_cast<double>(delayNum) * 1000 / delayDen);
+}
+
+nsPNGDecoder::AnimFrameInfo::AnimFrameInfo(png_structp aPNG, png_infop aInfo)
+    : mDispose(DisposalMethod::KEEP), mBlend(BlendMethod::OVER), mTimeout(0) {
+  png_byte dispose_op = png_get_next_frame_dispose_op(aPNG, aInfo);
+  png_byte blend_op = png_get_next_frame_blend_op(aPNG, aInfo);
+
+  if (dispose_op == PNG_DISPOSE_OP_PREVIOUS) {
+    mDispose = DisposalMethod::RESTORE_PREVIOUS;
+  } else if (dispose_op == PNG_DISPOSE_OP_BACKGROUND) {
+    mDispose = DisposalMethod::CLEAR;
+  } else {
+    mDispose = DisposalMethod::KEEP;
+  }
+
+  if (blend_op == PNG_BLEND_OP_SOURCE) {
+    mBlend = BlendMethod::SOURCE;
+  } else {
+    mBlend = BlendMethod::OVER;
+  }
+
+  mTimeout = GetNextFrameDelay(aPNG, aInfo);
+}
+#endif
+
+// First 8 bytes of a PNG file
+const uint8_t nsPNGDecoder::pngSignatureBytes[] = {137, 80, 78, 71,
+                                                   13,  10, 26, 10};
+
+nsPNGDecoder::nsPNGDecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mLexer(Transition::ToUnbuffered(State::FINISHED_PNG_DATA, State::PNG_DATA,
+                                      SIZE_MAX),
+             Transition::TerminateSuccess()),
+      mNextTransition(Transition::ContinueUnbuffered(State::PNG_DATA)),
+      mLastChunkLength(0),
+      mPNG(nullptr),
+      mInfo(nullptr),
+      mCMSLine(nullptr),
+      interlacebuf(nullptr),
+      mFormat(SurfaceFormat::UNKNOWN),
+      mChannels(0),
+      mPass(0),
+      mFrameIsHidden(false),
+      mDisablePremultipliedAlpha(false),
+      mGotInfoCallback(false),
+      mUsePipeTransform(false),
+      mNumFrames(0) {}
+
+nsPNGDecoder::~nsPNGDecoder() {
+  if (mPNG) {
+    png_destroy_read_struct(&mPNG, mInfo ? &mInfo : nullptr, nullptr);
+  }
+  if (mCMSLine) {
+    free(mCMSLine);
+  }
+  if (interlacebuf) {
+    free(interlacebuf);
+  }
+}
+
+nsPNGDecoder::TransparencyType nsPNGDecoder::GetTransparencyType(
+    const OrientedIntRect& aFrameRect) {
+  // Check if the image has a transparent color in its palette.
+  if (HasAlphaChannel()) {
+    return TransparencyType::eAlpha;
+  }
+  if (!aFrameRect.IsEqualEdges(FullFrame())) {
+    MOZ_ASSERT(HasAnimation());
+    return TransparencyType::eFrameRect;
+  }
+
+  return TransparencyType::eNone;
+}
+
+void nsPNGDecoder::PostHasTransparencyIfNeeded(
+    TransparencyType aTransparencyType) {
+  switch (aTransparencyType) {
+    case TransparencyType::eNone:
+      return;
+
+    case TransparencyType::eAlpha:
+      PostHasTransparency();
+      return;
+
+    case TransparencyType::eFrameRect:
+      // If the first frame of animated image doesn't draw into the whole image,
+      // then record that it is transparent. For subsequent frames, this doesn't
+      // affect transparency, because they're composited on top of all previous
+      // frames.
+      if (mNumFrames == 0) {
+        PostHasTransparency();
+      }
+      return;
+  }
+}
+
+// CreateFrame() is used for both simple and animated images.
+nsresult nsPNGDecoder::CreateFrame(const FrameInfo& aFrameInfo) {
+  MOZ_ASSERT(HasSize());
+  MOZ_ASSERT(!IsMetadataDecode());
+
+  // Check if we have transparency, and send notifications if needed.
+  auto transparency = GetTransparencyType(aFrameInfo.mFrameRect);
+  PostHasTransparencyIfNeeded(transparency);
+  mFormat = transparency == TransparencyType::eNone ? SurfaceFormat::OS_RGBX
+                                                    : SurfaceFormat::OS_RGBA;
+
+  // Make sure there's no animation or padding if we're downscaling.
+  MOZ_ASSERT_IF(Size() != OutputSize(), mNumFrames == 0);
+  MOZ_ASSERT_IF(Size() != OutputSize(), !GetImageMetadata().HasAnimation());
+  MOZ_ASSERT_IF(Size() != OutputSize(),
+                transparency != TransparencyType::eFrameRect);
+
+  Maybe<AnimationParams> animParams;
+#ifdef PNG_APNG_SUPPORTED
+  if (!IsFirstFrameDecode() && png_get_valid(mPNG, mInfo, PNG_INFO_acTL)) {
+    mAnimInfo = AnimFrameInfo(mPNG, mInfo);
+
+    if (mAnimInfo.mDispose == DisposalMethod::CLEAR) {
+      // We may have to display the background under this image during
+      // animation playback, so we regard it as transparent.
+      PostHasTransparency();
+    }
+
+    animParams.emplace(
+        AnimationParams{aFrameInfo.mFrameRect.ToUnknownRect(),
+                        FrameTimeout::FromRawMilliseconds(mAnimInfo.mTimeout),
+                        mNumFrames, mAnimInfo.mBlend, mAnimInfo.mDispose});
+  }
+#endif
+
+  // If this image is interlaced, we can display better quality intermediate
+  // results to the user by post processing them with ADAM7InterpolatingFilter.
+  SurfacePipeFlags pipeFlags = aFrameInfo.mIsInterlaced
+                                   ? SurfacePipeFlags::ADAM7_INTERPOLATE
+                                   : SurfacePipeFlags();
+
+  if (mNumFrames == 0) {
+    // The first frame may be displayed progressively.
+    pipeFlags |= SurfacePipeFlags::PROGRESSIVE_DISPLAY;
+  }
+
+  SurfaceFormat inFormat;
+  if (mTransform && !mUsePipeTransform) {
+    // QCMS will output in the correct format.
+    inFormat = mFormat;
+  } else if (transparency == TransparencyType::eAlpha) {
+    // We are outputting directly as RGBA, so we need to swap at this step.
+    inFormat = SurfaceFormat::R8G8B8A8;
+  } else {
+    // We have no alpha channel, so we need to unpack from RGB to BGRA.
+    inFormat = SurfaceFormat::R8G8B8;
+  }
+
+  // Only apply premultiplication if the frame has true alpha. If we ever
+  // support downscaling animated images, we will need to premultiply for frame
+  // rect transparency when downscaling as well.
+  if (transparency == TransparencyType::eAlpha && !mDisablePremultipliedAlpha) {
+    pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+  }
+
+  qcms_transform* pipeTransform = mUsePipeTransform ? mTransform : nullptr;
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), aFrameInfo.mFrameRect, inFormat, mFormat,
+      animParams, pipeTransform, pipeFlags);
+
+  if (!pipe) {
+    mPipe = SurfacePipe();
+    return NS_ERROR_FAILURE;
+  }
+
+  mPipe = std::move(*pipe);
+
+  mFrameRect = aFrameInfo.mFrameRect;
+  mPass = 0;
+
+  MOZ_LOG(sPNGDecoderAccountingLog, LogLevel::Debug,
+          ("PNGDecoderAccounting: nsPNGDecoder::CreateFrame -- created "
+           "image frame with %dx%d pixels for decoder %p",
+           mFrameRect.Width(), mFrameRect.Height(), this));
+
+  return NS_OK;
+}
+
+// set timeout and frame disposal method for the current frame
+void nsPNGDecoder::EndImageFrame() {
+  if (mFrameIsHidden) {
+    return;
+  }
+
+  mNumFrames++;
+
+  Opacity opacity = mFormat == SurfaceFormat::OS_RGBX
+                        ? Opacity::FULLY_OPAQUE
+                        : Opacity::SOME_TRANSPARENCY;
+
+  PostFrameStop(opacity);
+}
+
+nsresult nsPNGDecoder::InitInternal() {
+  mDisablePremultipliedAlpha =
+      bool(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+  static png_byte color_chunks[] = {99,  72, 82, 77, '\0',     // cHRM
+                                    105, 67, 67, 80, '\0'};    // iCCP
+  static png_byte unused_chunks[] = {98,  75, 71, 68,  '\0',   // bKGD
+                                     101, 88, 73, 102, '\0',   // eXIf
+                                     104, 73, 83, 84,  '\0',   // hIST
+                                     105, 84, 88, 116, '\0',   // iTXt
+                                     111, 70, 70, 115, '\0',   // oFFs
+                                     112, 67, 65, 76,  '\0',   // pCAL
+                                     115, 67, 65, 76,  '\0',   // sCAL
+                                     112, 72, 89, 115, '\0',   // pHYs
+                                     115, 66, 73, 84,  '\0',   // sBIT
+                                     115, 80, 76, 84,  '\0',   // sPLT
+                                     116, 69, 88, 116, '\0',   // tEXt
+                                     116, 73, 77, 69,  '\0',   // tIME
+                                     122, 84, 88, 116, '\0'};  // zTXt
+#endif
+
+  // Initialize the container's source image header
+  // Always decode to 24 bit pixdepth
+
+  mPNG = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr,
+                                nsPNGDecoder::error_callback,
+                                nsPNGDecoder::warning_callback);
+  if (!mPNG) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  mInfo = png_create_info_struct(mPNG);
+  if (!mInfo) {
+    png_destroy_read_struct(&mPNG, nullptr, nullptr);
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+  // Ignore unused chunks
+  if (mCMSMode == CMSMode::Off || IsMetadataDecode()) {
+    png_set_keep_unknown_chunks(mPNG, 1, color_chunks, 2);
+  }
+
+  png_set_keep_unknown_chunks(mPNG, 1, unused_chunks,
+                              (int)sizeof(unused_chunks) / 5);
+#endif
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+  png_set_user_limits(mPNG, MOZ_PNG_MAX_WIDTH, MOZ_PNG_MAX_HEIGHT);
+  png_set_chunk_malloc_max(mPNG, kPngMaxChunkSize);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+  // Disallow palette-index checking, for speed; we would ignore the warning
+  // anyhow.  This feature was added at libpng version 1.5.10 and is disabled
+  // in the embedded libpng but enabled by default in the system libpng.  This
+  // call also disables it in the system libpng, for decoding speed.
+  // Bug #745202.
+  png_set_check_for_invalid_index(mPNG, 0);
+#endif
+
+#ifdef PNG_SET_OPTION_SUPPORTED
+#  if defined(PNG_sRGB_PROFILE_CHECKS) && PNG_sRGB_PROFILE_CHECKS >= 0
+  // Skip checking of sRGB ICC profiles
+  png_set_option(mPNG, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON);
+#  endif
+
+#  ifdef PNG_MAXIMUM_INFLATE_WINDOW
+  // Force a larger zlib inflate window as some images in the wild have
+  // incorrectly set metadata (specifically CMF bits) which prevent us from
+  // decoding them otherwise.
+  png_set_option(mPNG, PNG_MAXIMUM_INFLATE_WINDOW, PNG_OPTION_ON);
+#  endif
+#endif
+
+  // use this as libpng "progressive pointer" (retrieve in callbacks)
+  png_set_progressive_read_fn(
+      mPNG, static_cast<png_voidp>(this), nsPNGDecoder::info_callback,
+      nsPNGDecoder::row_callback, nsPNGDecoder::end_callback);
+
+  return NS_OK;
+}
+
+LexerResult nsPNGDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                   IResumable* aOnResume) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  return mLexer.Lex(aIterator, aOnResume,
+                    [=](State aState, const char* aData, size_t aLength) {
+                      switch (aState) {
+                        case State::PNG_DATA:
+                          return ReadPNGData(aData, aLength);
+                        case State::FINISHED_PNG_DATA:
+                          return FinishedPNGData();
+                      }
+                      MOZ_CRASH("Unknown State");
+                    });
+}
+
+LexerTransition<nsPNGDecoder::State> nsPNGDecoder::ReadPNGData(
+    const char* aData, size_t aLength) {
+  // If we were waiting until after returning from a yield to call
+  // CreateFrame(), call it now.
+  if (mNextFrameInfo) {
+    if (NS_FAILED(CreateFrame(*mNextFrameInfo))) {
+      return Transition::TerminateFailure();
+    }
+
+    MOZ_ASSERT(mImageData, "Should have a buffer now");
+    mNextFrameInfo = Nothing();
+  }
+
+  // libpng uses setjmp/longjmp for error handling.
+  if (setjmp(png_jmpbuf(mPNG))) {
+    return Transition::TerminateFailure();
+  }
+
+  // Pass the data off to libpng.
+  mLastChunkLength = aLength;
+  mNextTransition = Transition::ContinueUnbuffered(State::PNG_DATA);
+  png_process_data(mPNG, mInfo,
+                   reinterpret_cast<unsigned char*>(const_cast<char*>((aData))),
+                   aLength);
+
+  // Make sure that we've reached a terminal state if decoding is done.
+  MOZ_ASSERT_IF(GetDecodeDone(), mNextTransition.NextStateIsTerminal());
+  MOZ_ASSERT_IF(HasError(), mNextTransition.NextStateIsTerminal());
+
+  // Continue with whatever transition the callback code requested. We
+  // initialized this to Transition::ContinueUnbuffered(State::PNG_DATA) above,
+  // so by default we just continue the unbuffered read.
+  return mNextTransition;
+}
+
+LexerTransition<nsPNGDecoder::State> nsPNGDecoder::FinishedPNGData() {
+  // Since we set up an unbuffered read for SIZE_MAX bytes, if we actually read
+  // all that data something is really wrong.
+  MOZ_ASSERT_UNREACHABLE("Read the entire address space?");
+  return Transition::TerminateFailure();
+}
+
+// Sets up gamma pre-correction in libpng before our callback gets called.
+// We need to do this if we don't end up with a CMS profile.
+static void PNGDoGammaCorrection(png_structp png_ptr, png_infop info_ptr) {
+  double aGamma;
+
+  if (png_get_gAMA(png_ptr, info_ptr, &aGamma)) {
+    if ((aGamma <= 0.0) || (aGamma > 21474.83)) {
+      aGamma = 0.45455;
+      png_set_gAMA(png_ptr, info_ptr, aGamma);
+    }
+    png_set_gamma(png_ptr, 2.2, aGamma);
+  } else {
+    png_set_gamma(png_ptr, 2.2, 0.45455);
+  }
+}
+
+// Adapted from http://www.littlecms.com/pngchrm.c example code
+uint32_t nsPNGDecoder::ReadColorProfile(png_structp png_ptr, png_infop info_ptr,
+                                        int color_type, bool* sRGBTag) {
+  // First try to see if iCCP chunk is present
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) {
+    png_uint_32 profileLen;
+    png_bytep profileData;
+    png_charp profileName;
+    int compression;
+
+    png_get_iCCP(png_ptr, info_ptr, &profileName, &compression, &profileData,
+                 &profileLen);
+
+    mInProfile = qcms_profile_from_memory((char*)profileData, profileLen);
+    if (mInProfile) {
+      uint32_t profileSpace = qcms_profile_get_color_space(mInProfile);
+
+      bool mismatch = false;
+      if (color_type & PNG_COLOR_MASK_COLOR) {
+        if (profileSpace != icSigRgbData) {
+          mismatch = true;
+        }
+      } else {
+        if (profileSpace == icSigRgbData) {
+          png_set_gray_to_rgb(png_ptr);
+        } else if (profileSpace != icSigGrayData) {
+          mismatch = true;
+        }
+      }
+
+      if (mismatch) {
+        qcms_profile_release(mInProfile);
+        mInProfile = nullptr;
+      } else {
+        return qcms_profile_get_rendering_intent(mInProfile);
+      }
+    }
+  }
+
+  // Check sRGB chunk
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sRGB)) {
+    *sRGBTag = true;
+
+    int fileIntent;
+    png_set_gray_to_rgb(png_ptr);
+    png_get_sRGB(png_ptr, info_ptr, &fileIntent);
+    uint32_t map[] = {QCMS_INTENT_PERCEPTUAL, QCMS_INTENT_RELATIVE_COLORIMETRIC,
+                      QCMS_INTENT_SATURATION,
+                      QCMS_INTENT_ABSOLUTE_COLORIMETRIC};
+    return map[fileIntent];
+  }
+
+  // Check gAMA/cHRM chunks
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA) &&
+      png_get_valid(png_ptr, info_ptr, PNG_INFO_cHRM)) {
+    qcms_CIE_xyYTRIPLE primaries;
+    qcms_CIE_xyY whitePoint;
+
+    png_get_cHRM(png_ptr, info_ptr, &whitePoint.x, &whitePoint.y,
+                 &primaries.red.x, &primaries.red.y, &primaries.green.x,
+                 &primaries.green.y, &primaries.blue.x, &primaries.blue.y);
+    whitePoint.Y = primaries.red.Y = primaries.green.Y = primaries.blue.Y = 1.0;
+
+    double gammaOfFile;
+
+    png_get_gAMA(png_ptr, info_ptr, &gammaOfFile);
+
+    mInProfile = qcms_profile_create_rgb_with_gamma(whitePoint, primaries,
+                                                    1.0 / gammaOfFile);
+
+    if (mInProfile) {
+      png_set_gray_to_rgb(png_ptr);
+    }
+  }
+
+  return QCMS_INTENT_PERCEPTUAL;  // Our default
+}
+
+void nsPNGDecoder::info_callback(png_structp png_ptr, png_infop info_ptr) {
+  png_uint_32 width, height;
+  int bit_depth, color_type, interlace_type, compression_type, filter_type;
+  unsigned int channels;
+
+  png_bytep trans = nullptr;
+  int num_trans = 0;
+
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  if (decoder->mGotInfoCallback) {
+    MOZ_LOG(sPNGLog, LogLevel::Warning,
+            ("libpng called info_callback more than once\n"));
+    return;
+  }
+
+  decoder->mGotInfoCallback = true;
+
+  // Always decode to 24-bit RGB or 32-bit RGBA
+  png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+               &interlace_type, &compression_type, &filter_type);
+
+  const OrientedIntRect frameRect(0, 0, width, height);
+
+  // Post our size to the superclass
+  decoder->PostSize(frameRect.Width(), frameRect.Height());
+
+  if (width > SurfaceCache::MaximumCapacity() / (bit_depth > 8 ? 16 : 8)) {
+    // libpng needs space to allocate two row buffers
+    png_error(decoder->mPNG, "Image is too wide");
+  }
+
+  if (decoder->HasError()) {
+    // Setting the size led to an error.
+    png_error(decoder->mPNG, "Sizing error");
+  }
+
+  if (color_type == PNG_COLOR_TYPE_PALETTE) {
+    png_set_expand(png_ptr);
+  }
+
+  if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+    png_set_expand(png_ptr);
+  }
+
+  if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
+    png_color_16p trans_values;
+    png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &trans_values);
+    // libpng doesn't reject a tRNS chunk with out-of-range samples
+    // so we check it here to avoid setting up a useless opacity
+    // channel or producing unexpected transparent pixels (bug #428045)
+    if (bit_depth < 16) {
+      png_uint_16 sample_max = (1 << bit_depth) - 1;
+      if ((color_type == PNG_COLOR_TYPE_GRAY &&
+           trans_values->gray > sample_max) ||
+          (color_type == PNG_COLOR_TYPE_RGB &&
+           (trans_values->red > sample_max ||
+            trans_values->green > sample_max ||
+            trans_values->blue > sample_max))) {
+        // clear the tRNS valid flag and release tRNS memory
+        png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+        num_trans = 0;
+      }
+    }
+    if (num_trans != 0) {
+      png_set_expand(png_ptr);
+    }
+  }
+
+  if (bit_depth == 16) {
+    png_set_scale_16(png_ptr);
+  }
+
+  // We only need to extract the color profile for non-metadata decodes. It is
+  // fairly expensive to read the profile and create the transform so we should
+  // avoid it if not necessary.
+  uint32_t intent = -1;
+  bool sRGBTag = false;
+  if (!decoder->IsMetadataDecode()) {
+    if (decoder->mCMSMode != CMSMode::Off) {
+      intent = gfxPlatform::GetRenderingIntent();
+      uint32_t pIntent =
+          decoder->ReadColorProfile(png_ptr, info_ptr, color_type, &sRGBTag);
+      // If we're not mandating an intent, use the one from the image.
+      if (intent == uint32_t(-1)) {
+        intent = pIntent;
+      }
+    }
+    if (!decoder->mInProfile || !decoder->GetCMSOutputProfile()) {
+      png_set_gray_to_rgb(png_ptr);
+
+      // only do gamma correction if CMS isn't entirely disabled
+      if (decoder->mCMSMode != CMSMode::Off) {
+        PNGDoGammaCorrection(png_ptr, info_ptr);
+      }
+    }
+  }
+
+  // Let libpng expand interlaced images.
+  const bool isInterlaced = interlace_type == PNG_INTERLACE_ADAM7;
+  if (isInterlaced) {
+    png_set_interlace_handling(png_ptr);
+  }
+
+  // now all of those things we set above are used to update various struct
+  // members and whatnot, after which we can get channels, rowbytes, etc.
+  png_read_update_info(png_ptr, info_ptr);
+  decoder->mChannels = channels = png_get_channels(png_ptr, info_ptr);
+
+  //---------------------------------------------------------------//
+  // copy PNG info into imagelib structs (formerly png_set_dims()) //
+  //---------------------------------------------------------------//
+
+  if (channels < 1 || channels > 4) {
+    png_error(decoder->mPNG, "Invalid number of channels");
+  }
+
+#ifdef PNG_APNG_SUPPORTED
+  bool isAnimated = png_get_valid(png_ptr, info_ptr, PNG_INFO_acTL);
+  if (isAnimated) {
+    int32_t rawTimeout = GetNextFrameDelay(png_ptr, info_ptr);
+    decoder->PostIsAnimated(FrameTimeout::FromRawMilliseconds(rawTimeout));
+
+    if (decoder->Size() != decoder->OutputSize() &&
+        !decoder->IsFirstFrameDecode()) {
+      MOZ_ASSERT_UNREACHABLE(
+          "Doing downscale-during-decode "
+          "for an animated image?");
+      png_error(decoder->mPNG, "Invalid downscale attempt");  // Abort decode.
+    }
+  }
+#endif
+
+  auto transparency = decoder->GetTransparencyType(frameRect);
+  if (decoder->IsMetadataDecode()) {
+    // If we are animated then the first frame rect is either:
+    // 1) the whole image if the IDAT chunk is part of the animation
+    // 2) the frame rect of the first fDAT chunk otherwise.
+    // If we are not animated then we want to make sure to call
+    // PostHasTransparency in the metadata decode if we need to. So it's
+    // okay to pass IntRect(0, 0, width, height) here for animated images;
+    // they will call with the proper first frame rect in the full decode.
+    decoder->PostHasTransparencyIfNeeded(transparency);
+
+    // We have the metadata we're looking for, so stop here, before we allocate
+    // buffers below.
+    return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+  }
+
+  if (decoder->mInProfile && decoder->GetCMSOutputProfile()) {
+    qcms_data_type inType;
+    qcms_data_type outType;
+
+    uint32_t profileSpace = qcms_profile_get_color_space(decoder->mInProfile);
+    decoder->mUsePipeTransform = profileSpace != icSigGrayData;
+    if (decoder->mUsePipeTransform) {
+      // If the transform happens with SurfacePipe, it will be in RGBA if we
+      // have an alpha channel, because the swizzle and premultiplication
+      // happens after color management. Otherwise it will be in BGRA because
+      // the swizzle happens at the start.
+      if (transparency == TransparencyType::eAlpha) {
+        inType = QCMS_DATA_RGBA_8;
+        outType = QCMS_DATA_RGBA_8;
+      } else {
+        inType = gfxPlatform::GetCMSOSRGBAType();
+        outType = inType;
+      }
+    } else {
+      if (color_type & PNG_COLOR_MASK_ALPHA) {
+        inType = QCMS_DATA_GRAYA_8;
+        outType = gfxPlatform::GetCMSOSRGBAType();
+      } else {
+        inType = QCMS_DATA_GRAY_8;
+        outType = gfxPlatform::GetCMSOSRGBAType();
+      }
+    }
+
+    decoder->mTransform = qcms_transform_create(decoder->mInProfile, inType,
+                                                decoder->GetCMSOutputProfile(),
+                                                outType, (qcms_intent)intent);
+  } else if ((sRGBTag && decoder->mCMSMode == CMSMode::TaggedOnly) ||
+             decoder->mCMSMode == CMSMode::All) {
+    // If the transform happens with SurfacePipe, it will be in RGBA if we
+    // have an alpha channel, because the swizzle and premultiplication
+    // happens after color management. Otherwise it will be in OS_RGBA because
+    // the swizzle happens at the start.
+    if (transparency == TransparencyType::eAlpha) {
+      decoder->mTransform =
+          decoder->GetCMSsRGBTransform(SurfaceFormat::R8G8B8A8);
+    } else {
+      decoder->mTransform =
+          decoder->GetCMSsRGBTransform(SurfaceFormat::OS_RGBA);
+    }
+    decoder->mUsePipeTransform = true;
+  }
+
+#ifdef PNG_APNG_SUPPORTED
+  if (isAnimated) {
+    png_set_progressive_frame_fn(png_ptr, nsPNGDecoder::frame_info_callback,
+                                 nullptr);
+  }
+
+  if (png_get_first_frame_is_hidden(png_ptr, info_ptr)) {
+    decoder->mFrameIsHidden = true;
+  } else {
+#endif
+    nsresult rv = decoder->CreateFrame(FrameInfo{frameRect, isInterlaced});
+    if (NS_FAILED(rv)) {
+      png_error(decoder->mPNG, "CreateFrame failed");
+    }
+    MOZ_ASSERT(decoder->mImageData, "Should have a buffer now");
+#ifdef PNG_APNG_SUPPORTED
+  }
+#endif
+
+  if (decoder->mTransform && !decoder->mUsePipeTransform) {
+    decoder->mCMSLine =
+        static_cast<uint8_t*>(malloc(sizeof(uint32_t) * frameRect.Width()));
+    if (!decoder->mCMSLine) {
+      png_error(decoder->mPNG, "malloc of mCMSLine failed");
+    }
+  }
+
+  if (interlace_type == PNG_INTERLACE_ADAM7) {
+    if (frameRect.Height() <
+        INT32_MAX / (frameRect.Width() * int32_t(channels))) {
+      const size_t bufferSize =
+          channels * frameRect.Width() * frameRect.Height();
+
+      if (bufferSize > SurfaceCache::MaximumCapacity()) {
+        png_error(decoder->mPNG, "Insufficient memory to deinterlace image");
+      }
+
+      decoder->interlacebuf = static_cast<uint8_t*>(malloc(bufferSize));
+    }
+    if (!decoder->interlacebuf) {
+      png_error(decoder->mPNG, "malloc of interlacebuf failed");
+    }
+  }
+}
+
+void nsPNGDecoder::PostInvalidationIfNeeded() {
+  Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+  if (!invalidRect) {
+    return;
+  }
+
+  PostInvalidation(invalidRect->mInputSpaceRect,
+                   Some(invalidRect->mOutputSpaceRect));
+}
+
+void nsPNGDecoder::row_callback(png_structp png_ptr, png_bytep new_row,
+                                png_uint_32 row_num, int pass) {
+  /* libpng comments:
+   *
+   * This function is called for every row in the image.  If the
+   * image is interlacing, and you turned on the interlace handler,
+   * this function will be called for every row in every pass.
+   * Some of these rows will not be changed from the previous pass.
+   * When the row is not changed, the new_row variable will be
+   * nullptr. The rows and passes are called in order, so you don't
+   * really need the row_num and pass, but I'm supplying them
+   * because it may make your life easier.
+   *
+   * For the non-nullptr rows of interlaced images, you must call
+   * png_progressive_combine_row() passing in the row and the
+   * old row.  You can call this function for nullptr rows (it will
+   * just return) and for non-interlaced images (it just does the
+   * memcpy for you) if it will make the code easier.  Thus, you
+   * can just do this for all cases:
+   *
+   *    png_progressive_combine_row(png_ptr, old_row, new_row);
+   *
+   * where old_row is what was displayed for previous rows.  Note
+   * that the first pass (pass == 0 really) will completely cover
+   * the old row, so the rows do not have to be initialized.  After
+   * the first pass (and only for interlaced images), you will have
+   * to pass the current row, and the function will combine the
+   * old row and the new row.
+   */
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  if (decoder->mFrameIsHidden) {
+    return;  // Skip this frame.
+  }
+
+  MOZ_ASSERT_IF(decoder->IsFirstFrameDecode(), decoder->mNumFrames == 0);
+
+  while (pass > decoder->mPass) {
+    // Advance to the next pass. We may have to do this multiple times because
+    // libpng will skip passes if the image is so small that no pixels have
+    // changed on a given pass, but ADAM7InterpolatingFilter needs to be reset
+    // once for every pass to perform interpolation properly.
+    decoder->mPipe.ResetToFirstRow();
+    decoder->mPass++;
+  }
+
+  const png_uint_32 height =
+      static_cast<png_uint_32>(decoder->mFrameRect.Height());
+
+  if (row_num >= height) {
+    // Bail if we receive extra rows. This is especially important because if we
+    // didn't, we might overflow the deinterlacing buffer.
+    MOZ_ASSERT_UNREACHABLE("libpng producing extra rows?");
+    return;
+  }
+
+  // Note that |new_row| may be null here, indicating that this is an interlaced
+  // image and |row_callback| is being called for a row that hasn't changed.
+  MOZ_ASSERT_IF(!new_row, decoder->interlacebuf);
+
+  if (decoder->interlacebuf) {
+    uint32_t width = uint32_t(decoder->mFrameRect.Width());
+
+    // We'll output the deinterlaced version of the row.
+    uint8_t* rowToWrite =
+        decoder->interlacebuf + (row_num * decoder->mChannels * width);
+
+    // Update the deinterlaced version of this row with the new data.
+    png_progressive_combine_row(png_ptr, rowToWrite, new_row);
+
+    decoder->WriteRow(rowToWrite);
+  } else {
+    decoder->WriteRow(new_row);
+  }
+}
+
+void nsPNGDecoder::WriteRow(uint8_t* aRow) {
+  MOZ_ASSERT(aRow);
+
+  uint8_t* rowToWrite = aRow;
+  uint32_t width = uint32_t(mFrameRect.Width());
+
+  // Apply color management to the row, if necessary, before writing it out.
+  // This is only needed for grayscale images.
+  if (mTransform && !mUsePipeTransform) {
+    MOZ_ASSERT(mCMSLine);
+    qcms_transform_data(mTransform, rowToWrite, mCMSLine, width);
+    rowToWrite = mCMSLine;
+  }
+
+  // Write this row to the SurfacePipe.
+  DebugOnly<WriteState> result =
+      mPipe.WriteBuffer(reinterpret_cast<uint32_t*>(rowToWrite));
+  MOZ_ASSERT(WriteState(result) != WriteState::FAILURE);
+
+  PostInvalidationIfNeeded();
+}
+
+void nsPNGDecoder::DoTerminate(png_structp aPNGStruct, TerminalState aState) {
+  // Stop processing data. Note that we intentionally ignore the return value of
+  // png_process_data_pause(), which tells us how many bytes of the data that
+  // was passed to png_process_data() have not been consumed yet, because now
+  // that we've reached a terminal state, we won't do any more decoding or call
+  // back into libpng anymore.
+  png_process_data_pause(aPNGStruct, /* save = */ false);
+
+  mNextTransition = aState == TerminalState::SUCCESS
+                        ? Transition::TerminateSuccess()
+                        : Transition::TerminateFailure();
+}
+
+void nsPNGDecoder::DoYield(png_structp aPNGStruct) {
+  // Pause data processing. png_process_data_pause() returns how many bytes of
+  // the data that was passed to png_process_data() have not been consumed yet.
+  // We use this information to tell StreamingLexer where to place us in the
+  // input stream when we come back from the yield.
+  png_size_t pendingBytes = png_process_data_pause(aPNGStruct,
+                                                   /* save = */ false);
+
+  MOZ_ASSERT(pendingBytes < mLastChunkLength);
+  size_t consumedBytes = mLastChunkLength - min(pendingBytes, mLastChunkLength);
+
+  mNextTransition =
+      Transition::ContinueUnbufferedAfterYield(State::PNG_DATA, consumedBytes);
+}
+
+nsresult nsPNGDecoder::FinishInternal() {
+  // We shouldn't be called in error cases.
+  MOZ_ASSERT(!HasError(), "Can't call FinishInternal on error!");
+
+  if (IsMetadataDecode()) {
+    return NS_OK;
+  }
+
+  int32_t loop_count = 0;
+#ifdef PNG_APNG_SUPPORTED
+  if (png_get_valid(mPNG, mInfo, PNG_INFO_acTL)) {
+    int32_t num_plays = png_get_num_plays(mPNG, mInfo);
+    loop_count = num_plays - 1;
+  }
+#endif
+
+  if (InFrame()) {
+    EndImageFrame();
+  }
+  PostDecodeDone(loop_count);
+
+  return NS_OK;
+}
+
+#ifdef PNG_APNG_SUPPORTED
+// got the header of a new frame that's coming
+void nsPNGDecoder::frame_info_callback(png_structp png_ptr,
+                                       png_uint_32 frame_num) {
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  // old frame is done
+  decoder->EndImageFrame();
+
+  const bool previousFrameWasHidden = decoder->mFrameIsHidden;
+
+  if (!previousFrameWasHidden && decoder->IsFirstFrameDecode()) {
+    // We're about to get a second non-hidden frame, but we only want the first.
+    // Stop decoding now. (And avoid allocating the unnecessary buffers below.)
+    return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+  }
+
+  // Only the first frame can be hidden, so unhide unconditionally here.
+  decoder->mFrameIsHidden = false;
+
+  // Save the information necessary to create the frame; we'll actually create
+  // it when we return from the yield.
+  const OrientedIntRect frameRect(
+      png_get_next_frame_x_offset(png_ptr, decoder->mInfo),
+      png_get_next_frame_y_offset(png_ptr, decoder->mInfo),
+      png_get_next_frame_width(png_ptr, decoder->mInfo),
+      png_get_next_frame_height(png_ptr, decoder->mInfo));
+  const bool isInterlaced = bool(decoder->interlacebuf);
+
+#  ifndef MOZ_EMBEDDED_LIBPNG
+  // if using system library, check frame_width and height against 0
+  if (frameRect.width == 0) {
+    png_error(png_ptr, "Frame width must not be 0");
+  }
+  if (frameRect.height == 0) {
+    png_error(png_ptr, "Frame height must not be 0");
+  }
+#  endif
+
+  const FrameInfo info{frameRect, isInterlaced};
+
+  // If the previous frame was hidden, skip the yield (which will mislead the
+  // caller, who will think the previous frame was real) and just allocate the
+  // new frame here.
+  if (previousFrameWasHidden) {
+    if (NS_FAILED(decoder->CreateFrame(info))) {
+      return decoder->DoTerminate(png_ptr, TerminalState::FAILURE);
+    }
+
+    MOZ_ASSERT(decoder->mImageData, "Should have a buffer now");
+    return;  // No yield, so we'll just keep decoding.
+  }
+
+  // Yield to the caller to notify them that the previous frame is now complete.
+  decoder->mNextFrameInfo = Some(info);
+  return decoder->DoYield(png_ptr);
+}
+#endif
+
+void nsPNGDecoder::end_callback(png_structp png_ptr, png_infop info_ptr) {
+  /* libpng comments:
+   *
+   * this function is called when the whole image has been read,
+   * including any chunks after the image (up to and including
+   * the IEND).  You will usually have the same info chunk as you
+   * had in the header, although some data may have been added
+   * to the comments and time fields.
+   *
+   * Most people won't do much here, perhaps setting a flag that
+   * marks the image as finished.
+   */
+
+  nsPNGDecoder* decoder =
+      static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+  // We shouldn't get here if we've hit an error
+  MOZ_ASSERT(!decoder->HasError(), "Finishing up PNG but hit error!");
+
+  return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+}
+
+void nsPNGDecoder::error_callback(png_structp png_ptr,
+                                  png_const_charp error_msg) {
+  MOZ_LOG(sPNGLog, LogLevel::Error, ("libpng error: %s\n", error_msg));
+  png_longjmp(png_ptr, 1);
+}
+
+void nsPNGDecoder::warning_callback(png_structp png_ptr,
+                                    png_const_charp warning_msg) {
+  MOZ_LOG(sPNGLog, LogLevel::Warning, ("libpng warning: %s\n", warning_msg));
+}
+
+Maybe<Telemetry::HistogramID> nsPNGDecoder::SpeedHistogram() const {
+  return Some(Telemetry::IMAGE_DECODE_SPEED_PNG);
+}
+
+bool nsPNGDecoder::IsValidICOResource() const {
+  // Only 32-bit RGBA PNGs are valid ICO resources; see here:
+  //   http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
+
+  // If there are errors in the call to png_get_IHDR, the error_callback in
+  // nsPNGDecoder.cpp is called.  In this error callback we do a longjmp, so
+  // we need to save the jump buffer here. Otherwise we'll end up without a
+  // proper callstack.
+  if (setjmp(png_jmpbuf(mPNG))) {
+    // We got here from a longjmp call indirectly from png_get_IHDR
+    return false;
+  }
+
+  png_uint_32 png_width,  // Unused
+      png_height;         // Unused
+
+  int png_bit_depth, png_color_type;
+
+  if (png_get_IHDR(mPNG, mInfo, &png_width, &png_height, &png_bit_depth,
+                   &png_color_type, nullptr, nullptr, nullptr)) {
+    return ((png_color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+             png_color_type == PNG_COLOR_TYPE_RGB) &&
+            png_bit_depth == 8);
+  } else {
+    return false;
+  }
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsPNGDecoder.h b/image/decoders/nsPNGDecoder.h
new file mode 100644
index 0000000000..89d66fa5eb
--- /dev/null
+++ b/image/decoders/nsPNGDecoder.h
@@ -0,0 +1,148 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsPNGDecoder_h
+#define mozilla_image_decoders_nsPNGDecoder_h
+
+#include "Decoder.h"
+#include "png.h"
+#include "StreamingLexer.h"
+#include "SurfacePipe.h"
+#include "mozilla/gfx/Swizzle.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+class nsPNGDecoder : public Decoder {
+ public:
+  virtual ~nsPNGDecoder();
+
+  /// @return true if this PNG is a valid ICO resource.
+  bool IsValidICOResource() const override;
+
+  DecoderType GetType() const override { return DecoderType::PNG; }
+
+ protected:
+  nsresult InitInternal() override;
+  nsresult FinishInternal() override;
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+
+  Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsPNGDecoder(RasterImage* aImage);
+
+  /// The information necessary to create a frame.
+  struct FrameInfo {
+    OrientedIntRect mFrameRect;
+    bool mIsInterlaced;
+  };
+
+  nsresult CreateFrame(const FrameInfo& aFrameInfo);
+  void EndImageFrame();
+
+  uint32_t ReadColorProfile(png_structp png_ptr, png_infop info_ptr,
+                            int color_type, bool* sRGBTag);
+
+  bool HasAlphaChannel() const { return mChannels == 2 || mChannels == 4; }
+
+  enum class TransparencyType { eNone, eAlpha, eFrameRect };
+
+  TransparencyType GetTransparencyType(const OrientedIntRect& aFrameRect);
+  void PostHasTransparencyIfNeeded(TransparencyType aTransparencyType);
+
+  void PostInvalidationIfNeeded();
+
+  void WriteRow(uint8_t* aRow);
+
+  // Convenience methods to make interacting with StreamingLexer from inside
+  // a libpng callback easier.
+  void DoTerminate(png_structp aPNGStruct, TerminalState aState);
+  void DoYield(png_structp aPNGStruct);
+
+  enum class State { PNG_DATA, FINISHED_PNG_DATA };
+
+  LexerTransition<State> ReadPNGData(const char* aData, size_t aLength);
+  LexerTransition<State> FinishedPNGData();
+
+  StreamingLexer<State> mLexer;
+
+  // The next lexer state transition. We need to store it here because we can't
+  // directly return arbitrary values from libpng callbacks.
+  LexerTransition<State> mNextTransition;
+
+  // We yield to the caller every time we finish decoding a frame. When this
+  // happens, we need to allocate the next frame after returning from the yield.
+  // |mNextFrameInfo| is used to store the information needed to allocate the
+  // next frame.
+  Maybe<FrameInfo> mNextFrameInfo;
+
+  // The length of the last chunk of data passed to ReadPNGData(). We use this
+  // to arrange to arrive back at the correct spot in the data after yielding.
+  size_t mLastChunkLength;
+
+ public:
+  png_structp mPNG;
+  png_infop mInfo;
+  OrientedIntRect mFrameRect;
+  uint8_t* mCMSLine;
+  uint8_t* interlacebuf;
+  gfx::SurfaceFormat mFormat;
+
+  uint8_t mChannels;
+  uint8_t mPass;
+  bool mFrameIsHidden;
+  bool mDisablePremultipliedAlpha;
+  bool mGotInfoCallback;
+  bool mUsePipeTransform;
+
+  struct AnimFrameInfo {
+    AnimFrameInfo();
+#ifdef PNG_APNG_SUPPORTED
+    AnimFrameInfo(png_structp aPNG, png_infop aInfo);
+#endif
+
+    DisposalMethod mDispose;
+    BlendMethod mBlend;
+    int32_t mTimeout;
+  };
+
+  AnimFrameInfo mAnimInfo;
+
+  SurfacePipe mPipe;  /// The SurfacePipe used to write to the output surface.
+
+  // The number of frames we've finished.
+  uint32_t mNumFrames;
+
+  // libpng callbacks
+  // We put these in the class so that they can access protected members.
+  static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr);
+  static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row,
+                                  png_uint_32 row_num, int pass);
+#ifdef PNG_APNG_SUPPORTED
+  static void PNGAPI frame_info_callback(png_structp png_ptr,
+                                         png_uint_32 frame_num);
+#endif
+  static void PNGAPI end_callback(png_structp png_ptr, png_infop info_ptr);
+  static void PNGAPI error_callback(png_structp png_ptr,
+                                    png_const_charp error_msg);
+  static void PNGAPI warning_callback(png_structp png_ptr,
+                                      png_const_charp warning_msg);
+
+  // This is defined in the PNG spec as an invariant. We use it to
+  // do manual validation without libpng.
+  static const uint8_t pngSignatureBytes[];
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsPNGDecoder_h
diff --git a/image/decoders/nsWebPDecoder.cpp b/image/decoders/nsWebPDecoder.cpp
new file mode 100644
index 0000000000..e7467f0066
--- /dev/null
+++ b/image/decoders/nsWebPDecoder.cpp
@@ -0,0 +1,605 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h"  // Must appear first
+#include "gfxPlatform.h"
+#include "mozilla/TelemetryHistogramEnums.h"
+#include "nsWebPDecoder.h"
+
+#include "RasterImage.h"
+#include "SurfacePipeFactory.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+namespace image {
+
+static LazyLogModule sWebPLog("WebPDecoder");
+
+nsWebPDecoder::nsWebPDecoder(RasterImage* aImage)
+    : Decoder(aImage),
+      mDecoder(nullptr),
+      mBlend(BlendMethod::OVER),
+      mDisposal(DisposalMethod::KEEP),
+      mTimeout(FrameTimeout::Forever()),
+      mFormat(SurfaceFormat::OS_RGBX),
+      mLastRow(0),
+      mCurrentFrame(0),
+      mData(nullptr),
+      mLength(0),
+      mIteratorComplete(false),
+      mNeedDemuxer(true),
+      mGotColorProfile(false) {
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::nsWebPDecoder", this));
+}
+
+nsWebPDecoder::~nsWebPDecoder() {
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::~nsWebPDecoder", this));
+  if (mDecoder) {
+    WebPIDelete(mDecoder);
+    WebPFreeDecBuffer(&mBuffer);
+  }
+}
+
+LexerResult nsWebPDecoder::ReadData() {
+  MOZ_ASSERT(mData);
+  MOZ_ASSERT(mLength > 0);
+
+  WebPDemuxer* demuxer = nullptr;
+  bool complete = mIteratorComplete;
+
+  if (mNeedDemuxer) {
+    WebPDemuxState state;
+    WebPData fragment;
+    fragment.bytes = mData;
+    fragment.size = mLength;
+
+    demuxer = WebPDemuxPartial(&fragment, &state);
+    if (state == WEBP_DEMUX_PARSE_ERROR) {
+      MOZ_LOG(
+          sWebPLog, LogLevel::Error,
+          ("[this=%p] nsWebPDecoder::ReadData -- demux parse error\n", this));
+      WebPDemuxDelete(demuxer);
+      return LexerResult(TerminalState::FAILURE);
+    }
+
+    if (state == WEBP_DEMUX_PARSING_HEADER) {
+      WebPDemuxDelete(demuxer);
+      return LexerResult(Yield::NEED_MORE_DATA);
+    }
+
+    if (!demuxer) {
+      MOZ_LOG(sWebPLog, LogLevel::Error,
+              ("[this=%p] nsWebPDecoder::ReadData -- no demuxer\n", this));
+      return LexerResult(TerminalState::FAILURE);
+    }
+
+    complete = complete || state == WEBP_DEMUX_DONE;
+  }
+
+  LexerResult rv(TerminalState::FAILURE);
+  if (!HasSize()) {
+    rv = ReadHeader(demuxer, complete);
+  } else {
+    rv = ReadPayload(demuxer, complete);
+  }
+
+  WebPDemuxDelete(demuxer);
+  return rv;
+}
+
+LexerResult nsWebPDecoder::DoDecode(SourceBufferIterator& aIterator,
+                                    IResumable* aOnResume) {
+  while (true) {
+    SourceBufferIterator::State state = SourceBufferIterator::COMPLETE;
+    if (!mIteratorComplete) {
+      state = aIterator.AdvanceOrScheduleResume(SIZE_MAX, aOnResume);
+
+      // We need to remember since we can't advance a complete iterator.
+      mIteratorComplete = state == SourceBufferIterator::COMPLETE;
+    }
+
+    if (state == SourceBufferIterator::WAITING) {
+      return LexerResult(Yield::NEED_MORE_DATA);
+    }
+
+    LexerResult rv = UpdateBuffer(aIterator, state);
+    if (rv.is<Yield>() && rv.as<Yield>() == Yield::NEED_MORE_DATA) {
+      // We need to check the iterator to see if more is available before
+      // giving up unless we are already complete.
+      if (mIteratorComplete) {
+        MOZ_LOG(sWebPLog, LogLevel::Error,
+                ("[this=%p] nsWebPDecoder::DoDecode -- read all data, "
+                 "but needs more\n",
+                 this));
+        return LexerResult(TerminalState::FAILURE);
+      }
+      continue;
+    }
+
+    return rv;
+  }
+}
+
+LexerResult nsWebPDecoder::UpdateBuffer(SourceBufferIterator& aIterator,
+                                        SourceBufferIterator::State aState) {
+  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+  switch (aState) {
+    case SourceBufferIterator::READY:
+      if (!aIterator.IsContiguous()) {
+        // We need to buffer. This should be rare, but expensive.
+        break;
+      }
+      if (!mData) {
+        // For as long as we hold onto an iterator, we know the data pointers
+        // to the chunks cannot change underneath us, so save the pointer to
+        // the first block.
+        MOZ_ASSERT(mLength == 0);
+        mData = reinterpret_cast<const uint8_t*>(aIterator.Data());
+      }
+      mLength += aIterator.Length();
+      return ReadData();
+    case SourceBufferIterator::COMPLETE:
+      if (!mData) {
+        // We must have hit an error, such as an OOM, when buffering the
+        // first set of encoded data.
+        MOZ_LOG(
+            sWebPLog, LogLevel::Error,
+            ("[this=%p] nsWebPDecoder::DoDecode -- complete no data\n", this));
+        return LexerResult(TerminalState::FAILURE);
+      }
+      return ReadData();
+    default:
+      MOZ_LOG(sWebPLog, LogLevel::Error,
+              ("[this=%p] nsWebPDecoder::DoDecode -- bad state\n", this));
+      return LexerResult(TerminalState::FAILURE);
+  }
+
+  // We need to buffer. If we have no data buffered, we need to get everything
+  // from the first chunk of the source buffer before appending the new data.
+  if (mBufferedData.empty()) {
+    MOZ_ASSERT(mData);
+    MOZ_ASSERT(mLength > 0);
+
+    if (!mBufferedData.append(mData, mLength)) {
+      MOZ_LOG(sWebPLog, LogLevel::Error,
+              ("[this=%p] nsWebPDecoder::DoDecode -- oom, initialize %zu\n",
+               this, mLength));
+      return LexerResult(TerminalState::FAILURE);
+    }
+
+    MOZ_LOG(sWebPLog, LogLevel::Debug,
+            ("[this=%p] nsWebPDecoder::DoDecode -- buffered %zu bytes\n", this,
+             mLength));
+  }
+
+  // Append the incremental data from the iterator.
+  if (!mBufferedData.append(aIterator.Data(), aIterator.Length())) {
+    MOZ_LOG(sWebPLog, LogLevel::Error,
+            ("[this=%p] nsWebPDecoder::DoDecode -- oom, append %zu on %zu\n",
+             this, aIterator.Length(), mBufferedData.length()));
+    return LexerResult(TerminalState::FAILURE);
+  }
+
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::DoDecode -- buffered %zu -> %zu bytes\n",
+           this, aIterator.Length(), mBufferedData.length()));
+  mData = mBufferedData.begin();
+  mLength = mBufferedData.length();
+  return ReadData();
+}
+
+nsresult nsWebPDecoder::CreateFrame(const OrientedIntRect& aFrameRect) {
+  MOZ_ASSERT(HasSize());
+  MOZ_ASSERT(!mDecoder);
+
+  MOZ_LOG(
+      sWebPLog, LogLevel::Debug,
+      ("[this=%p] nsWebPDecoder::CreateFrame -- frame %u, (%d, %d) %d x %d\n",
+       this, mCurrentFrame, aFrameRect.x, aFrameRect.y, aFrameRect.width,
+       aFrameRect.height));
+
+  if (aFrameRect.width <= 0 || aFrameRect.height <= 0) {
+    MOZ_LOG(sWebPLog, LogLevel::Error,
+            ("[this=%p] nsWebPDecoder::CreateFrame -- bad frame rect\n", this));
+    return NS_ERROR_FAILURE;
+  }
+
+  // If this is our first frame in an animation and it doesn't cover the
+  // full frame, then we are transparent even if there is no alpha
+  if (mCurrentFrame == 0 && !aFrameRect.IsEqualEdges(FullFrame())) {
+    MOZ_ASSERT(HasAnimation());
+    mFormat = SurfaceFormat::OS_RGBA;
+    PostHasTransparency();
+  }
+
+  WebPInitDecBuffer(&mBuffer);
+
+  switch (SurfaceFormat::OS_RGBA) {
+    case SurfaceFormat::B8G8R8A8:
+      mBuffer.colorspace = MODE_BGRA;
+      break;
+    case SurfaceFormat::A8R8G8B8:
+      mBuffer.colorspace = MODE_ARGB;
+      break;
+    case SurfaceFormat::R8G8B8A8:
+      mBuffer.colorspace = MODE_RGBA;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unknown OS_RGBA");
+      return NS_ERROR_FAILURE;
+  }
+
+  mDecoder = WebPINewDecoder(&mBuffer);
+  if (!mDecoder) {
+    MOZ_LOG(sWebPLog, LogLevel::Error,
+            ("[this=%p] nsWebPDecoder::CreateFrame -- create decoder error\n",
+             this));
+    return NS_ERROR_FAILURE;
+  }
+
+  // WebP doesn't guarantee that the alpha generated matches the hint in the
+  // header, so we always need to claim the input is BGRA. If the output is
+  // BGRX, swizzling will mask off the alpha channel.
+  SurfaceFormat inFormat = SurfaceFormat::OS_RGBA;
+
+  SurfacePipeFlags pipeFlags = SurfacePipeFlags();
+  if (mFormat == SurfaceFormat::OS_RGBA &&
+      !(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA)) {
+    pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+  }
+
+  Maybe<AnimationParams> animParams;
+  if (!IsFirstFrameDecode()) {
+    animParams.emplace(aFrameRect.ToUnknownRect(), mTimeout, mCurrentFrame,
+                       mBlend, mDisposal);
+  }
+
+  Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+      this, Size(), OutputSize(), aFrameRect, inFormat, mFormat, animParams,
+      mTransform, pipeFlags);
+  if (!pipe) {
+    MOZ_LOG(sWebPLog, LogLevel::Error,
+            ("[this=%p] nsWebPDecoder::CreateFrame -- no pipe\n", this));
+    return NS_ERROR_FAILURE;
+  }
+
+  mFrameRect = aFrameRect;
+  mPipe = std::move(*pipe);
+  return NS_OK;
+}
+
+void nsWebPDecoder::EndFrame() {
+  MOZ_ASSERT(HasSize());
+  MOZ_ASSERT(mDecoder);
+
+  auto opacity = mFormat == SurfaceFormat::OS_RGBA ? Opacity::SOME_TRANSPARENCY
+                                                   : Opacity::FULLY_OPAQUE;
+
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::EndFrame -- frame %u, opacity %d, "
+           "disposal %d, timeout %d, blend %d\n",
+           this, mCurrentFrame, (int)opacity, (int)mDisposal,
+           mTimeout.AsEncodedValueDeprecated(), (int)mBlend));
+
+  PostFrameStop(opacity);
+  WebPIDelete(mDecoder);
+  WebPFreeDecBuffer(&mBuffer);
+  mDecoder = nullptr;
+  mLastRow = 0;
+  ++mCurrentFrame;
+}
+
+void nsWebPDecoder::ApplyColorProfile(const char* aProfile, size_t aLength) {
+  MOZ_ASSERT(!mGotColorProfile);
+  mGotColorProfile = true;
+
+  if (mCMSMode == CMSMode::Off || !GetCMSOutputProfile() ||
+      (mCMSMode == CMSMode::TaggedOnly && !aProfile)) {
+    return;
+  }
+
+  if (!aProfile) {
+    MOZ_LOG(sWebPLog, LogLevel::Debug,
+            ("[this=%p] nsWebPDecoder::ApplyColorProfile -- not tagged, use "
+             "sRGB transform\n",
+             this));
+    mTransform = GetCMSsRGBTransform(SurfaceFormat::OS_RGBA);
+    return;
+  }
+
+  mInProfile = qcms_profile_from_memory(aProfile, aLength);
+  if (!mInProfile) {
+    MOZ_LOG(
+        sWebPLog, LogLevel::Error,
+        ("[this=%p] nsWebPDecoder::ApplyColorProfile -- bad color profile\n",
+         this));
+    return;
+  }
+
+  uint32_t profileSpace = qcms_profile_get_color_space(mInProfile);
+  if (profileSpace != icSigRgbData) {
+    // WebP doesn't produce grayscale data, this must be corrupt.
+    MOZ_LOG(sWebPLog, LogLevel::Error,
+            ("[this=%p] nsWebPDecoder::ApplyColorProfile -- ignoring non-rgb "
+             "color profile\n",
+             this));
+    return;
+  }
+
+  // Calculate rendering intent.
+  int intent = gfxPlatform::GetRenderingIntent();
+  if (intent == -1) {
+    intent = qcms_profile_get_rendering_intent(mInProfile);
+  }
+
+  // Create the color management transform.
+  qcms_data_type type = gfxPlatform::GetCMSOSRGBAType();
+  mTransform = qcms_transform_create(mInProfile, type, GetCMSOutputProfile(),
+                                     type, (qcms_intent)intent);
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::ApplyColorProfile -- use tagged "
+           "transform\n",
+           this));
+}
+
+LexerResult nsWebPDecoder::ReadHeader(WebPDemuxer* aDemuxer, bool aIsComplete) {
+  MOZ_ASSERT(aDemuxer);
+
+  MOZ_LOG(
+      sWebPLog, LogLevel::Debug,
+      ("[this=%p] nsWebPDecoder::ReadHeader -- %zu bytes\n", this, mLength));
+
+  uint32_t flags = WebPDemuxGetI(aDemuxer, WEBP_FF_FORMAT_FLAGS);
+
+  if (!IsMetadataDecode() && !mGotColorProfile) {
+    if (flags & WebPFeatureFlags::ICCP_FLAG) {
+      WebPChunkIterator iter;
+      if (WebPDemuxGetChunk(aDemuxer, "ICCP", 1, &iter)) {
+        ApplyColorProfile(reinterpret_cast<const char*>(iter.chunk.bytes),
+                          iter.chunk.size);
+        WebPDemuxReleaseChunkIterator(&iter);
+
+      } else {
+        if (!aIsComplete) {
+          return LexerResult(Yield::NEED_MORE_DATA);
+        }
+
+        MOZ_LOG(sWebPLog, LogLevel::Warning,
+                ("[this=%p] nsWebPDecoder::ReadHeader header specified ICCP "
+                 "but no ICCP chunk found, ignoring\n",
+                 this));
+
+        ApplyColorProfile(nullptr, 0);
+      }
+    } else {
+      ApplyColorProfile(nullptr, 0);
+    }
+  }
+
+  if (flags & WebPFeatureFlags::ANIMATION_FLAG) {
+    // A metadata decode expects to get the correct first frame timeout which
+    // sadly is not provided by the normal WebP header parsing.
+    WebPIterator iter;
+    if (!WebPDemuxGetFrame(aDemuxer, 1, &iter)) {
+      return aIsComplete ? LexerResult(TerminalState::FAILURE)
+                         : LexerResult(Yield::NEED_MORE_DATA);
+    }
+
+    PostIsAnimated(FrameTimeout::FromRawMilliseconds(iter.duration));
+    WebPDemuxReleaseIterator(&iter);
+  } else {
+    // Single frames don't need a demuxer to be created.
+    mNeedDemuxer = false;
+  }
+
+  uint32_t width = WebPDemuxGetI(aDemuxer, WEBP_FF_CANVAS_WIDTH);
+  uint32_t height = WebPDemuxGetI(aDemuxer, WEBP_FF_CANVAS_HEIGHT);
+  if (width > INT32_MAX || height > INT32_MAX) {
+    return LexerResult(TerminalState::FAILURE);
+  }
+
+  PostSize(width, height);
+
+  bool alpha = flags & WebPFeatureFlags::ALPHA_FLAG;
+  if (alpha) {
+    mFormat = SurfaceFormat::OS_RGBA;
+    PostHasTransparency();
+  }
+
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::ReadHeader -- %u x %u, alpha %d, "
+           "animation %d, metadata decode %d, first frame decode %d\n",
+           this, width, height, alpha, HasAnimation(), IsMetadataDecode(),
+           IsFirstFrameDecode()));
+
+  if (IsMetadataDecode()) {
+    return LexerResult(TerminalState::SUCCESS);
+  }
+
+  return ReadPayload(aDemuxer, aIsComplete);
+}
+
+LexerResult nsWebPDecoder::ReadPayload(WebPDemuxer* aDemuxer,
+                                       bool aIsComplete) {
+  if (!HasAnimation()) {
+    auto rv = ReadSingle(mData, mLength, FullFrame());
+    if (rv.is<TerminalState>() &&
+        rv.as<TerminalState>() == TerminalState::SUCCESS) {
+      PostDecodeDone();
+    }
+    return rv;
+  }
+  return ReadMultiple(aDemuxer, aIsComplete);
+}
+
+LexerResult nsWebPDecoder::ReadSingle(const uint8_t* aData, size_t aLength,
+                                      const OrientedIntRect& aFrameRect) {
+  MOZ_ASSERT(!IsMetadataDecode());
+  MOZ_ASSERT(aData);
+  MOZ_ASSERT(aLength > 0);
+
+  MOZ_LOG(
+      sWebPLog, LogLevel::Debug,
+      ("[this=%p] nsWebPDecoder::ReadSingle -- %zu bytes\n", this, aLength));
+
+  if (!mDecoder && NS_FAILED(CreateFrame(aFrameRect))) {
+    return LexerResult(TerminalState::FAILURE);
+  }
+
+  bool complete;
+  do {
+    VP8StatusCode status = WebPIUpdate(mDecoder, aData, aLength);
+    switch (status) {
+      case VP8_STATUS_OK:
+        complete = true;
+        break;
+      case VP8_STATUS_SUSPENDED:
+        complete = false;
+        break;
+      default:
+        MOZ_LOG(sWebPLog, LogLevel::Error,
+                ("[this=%p] nsWebPDecoder::ReadSingle -- append error %d\n",
+                 this, status));
+        return LexerResult(TerminalState::FAILURE);
+    }
+
+    int lastRow = -1;
+    int width = 0;
+    int height = 0;
+    int stride = 0;
+    uint8_t* rowStart =
+        WebPIDecGetRGB(mDecoder, &lastRow, &width, &height, &stride);
+
+    MOZ_LOG(
+        sWebPLog, LogLevel::Debug,
+        ("[this=%p] nsWebPDecoder::ReadSingle -- complete %d, read %d rows, "
+         "has %d rows available\n",
+         this, complete, mLastRow, lastRow));
+
+    if (!rowStart || lastRow == -1 || lastRow == mLastRow) {
+      return LexerResult(Yield::NEED_MORE_DATA);
+    }
+
+    if (width != mFrameRect.width || height != mFrameRect.height ||
+        stride < mFrameRect.width * 4 || lastRow > mFrameRect.height) {
+      MOZ_LOG(sWebPLog, LogLevel::Error,
+              ("[this=%p] nsWebPDecoder::ReadSingle -- bad (w,h,s) = (%d, %d, "
+               "%d)\n",
+               this, width, height, stride));
+      return LexerResult(TerminalState::FAILURE);
+    }
+
+    for (int row = mLastRow; row < lastRow; row++) {
+      uint32_t* src = reinterpret_cast<uint32_t*>(rowStart + row * stride);
+      WriteState result = mPipe.WriteBuffer(src);
+
+      Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+      if (invalidRect) {
+        PostInvalidation(invalidRect->mInputSpaceRect,
+                         Some(invalidRect->mOutputSpaceRect));
+      }
+
+      if (result == WriteState::FAILURE) {
+        MOZ_LOG(sWebPLog, LogLevel::Error,
+                ("[this=%p] nsWebPDecoder::ReadSingle -- write pixels error\n",
+                 this));
+        return LexerResult(TerminalState::FAILURE);
+      }
+
+      if (result == WriteState::FINISHED) {
+        MOZ_ASSERT(row == lastRow - 1, "There was more data to read?");
+        complete = true;
+        break;
+      }
+    }
+
+    mLastRow = lastRow;
+  } while (!complete);
+
+  if (!complete) {
+    return LexerResult(Yield::NEED_MORE_DATA);
+  }
+
+  EndFrame();
+  return LexerResult(TerminalState::SUCCESS);
+}
+
+LexerResult nsWebPDecoder::ReadMultiple(WebPDemuxer* aDemuxer,
+                                        bool aIsComplete) {
+  MOZ_ASSERT(!IsMetadataDecode());
+  MOZ_ASSERT(aDemuxer);
+
+  MOZ_LOG(sWebPLog, LogLevel::Debug,
+          ("[this=%p] nsWebPDecoder::ReadMultiple\n", this));
+
+  bool complete = aIsComplete;
+  WebPIterator iter;
+  auto rv = LexerResult(Yield::NEED_MORE_DATA);
+  if (WebPDemuxGetFrame(aDemuxer, mCurrentFrame + 1, &iter)) {
+    switch (iter.blend_method) {
+      case WEBP_MUX_BLEND:
+        mBlend = BlendMethod::OVER;
+        break;
+      case WEBP_MUX_NO_BLEND:
+        mBlend = BlendMethod::SOURCE;
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE("Unhandled blend method");
+        break;
+    }
+
+    switch (iter.dispose_method) {
+      case WEBP_MUX_DISPOSE_NONE:
+        mDisposal = DisposalMethod::KEEP;
+        break;
+      case WEBP_MUX_DISPOSE_BACKGROUND:
+        mDisposal = DisposalMethod::CLEAR;
+        break;
+      default:
+        MOZ_ASSERT_UNREACHABLE("Unhandled dispose method");
+        break;
+    }
+
+    mFormat = iter.has_alpha || mCurrentFrame > 0 ? SurfaceFormat::OS_RGBA
+                                                  : SurfaceFormat::OS_RGBX;
+    mTimeout = FrameTimeout::FromRawMilliseconds(iter.duration);
+    OrientedIntRect frameRect(iter.x_offset, iter.y_offset, iter.width,
+                              iter.height);
+
+    rv = ReadSingle(iter.fragment.bytes, iter.fragment.size, frameRect);
+    complete = complete && !WebPDemuxNextFrame(&iter);
+    WebPDemuxReleaseIterator(&iter);
+  }
+
+  if (rv.is<TerminalState>() &&
+      rv.as<TerminalState>() == TerminalState::SUCCESS) {
+    // If we extracted one frame, and it is not the last, we need to yield to
+    // the lexer to allow the upper layers to acknowledge the frame.
+    if (!complete && !IsFirstFrameDecode()) {
+      rv = LexerResult(Yield::OUTPUT_AVAILABLE);
+    } else {
+      uint32_t loopCount = WebPDemuxGetI(aDemuxer, WEBP_FF_LOOP_COUNT);
+
+      MOZ_LOG(sWebPLog, LogLevel::Debug,
+              ("[this=%p] nsWebPDecoder::ReadMultiple -- loop count %u\n", this,
+               loopCount));
+      PostDecodeDone(loopCount - 1);
+    }
+  }
+
+  return rv;
+}
+
+Maybe<Telemetry::HistogramID> nsWebPDecoder::SpeedHistogram() const {
+  return Some(Telemetry::IMAGE_DECODE_SPEED_WEBP);
+}
+
+}  // namespace image
+}  // namespace mozilla
diff --git a/image/decoders/nsWebPDecoder.h b/image/decoders/nsWebPDecoder.h
new file mode 100644
index 0000000000..e69122d19a
--- /dev/null
+++ b/image/decoders/nsWebPDecoder.h
@@ -0,0 +1,105 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_decoders_nsWebPDecoder_h
+#define mozilla_image_decoders_nsWebPDecoder_h
+
+#include "Decoder.h"
+#include "webp/demux.h"
+#include "StreamingLexer.h"
+#include "SurfacePipe.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+class nsWebPDecoder final : public Decoder {
+ public:
+  virtual ~nsWebPDecoder();
+
+  DecoderType GetType() const override { return DecoderType::WEBP; }
+
+ protected:
+  LexerResult DoDecode(SourceBufferIterator& aIterator,
+                       IResumable* aOnResume) override;
+  Maybe<Telemetry::HistogramID> SpeedHistogram() const override;
+
+ private:
+  friend class DecoderFactory;
+
+  // Decoders should only be instantiated via DecoderFactory.
+  explicit nsWebPDecoder(RasterImage* aImage);
+
+  void ApplyColorProfile(const char* aProfile, size_t aLength);
+
+  LexerResult UpdateBuffer(SourceBufferIterator& aIterator,
+                           SourceBufferIterator::State aState);
+  LexerResult ReadData();
+  LexerResult ReadHeader(WebPDemuxer* aDemuxer, bool aIsComplete);
+  LexerResult ReadPayload(WebPDemuxer* aDemuxer, bool aIsComplete);
+
+  nsresult CreateFrame(const OrientedIntRect& aFrameRect);
+  void EndFrame();
+
+  LexerResult ReadSingle(const uint8_t* aData, size_t aLength,
+                         const OrientedIntRect& aFrameRect);
+
+  LexerResult ReadMultiple(WebPDemuxer* aDemuxer, bool aIsComplete);
+
+  /// The SurfacePipe used to write to the output surface.
+  SurfacePipe mPipe;
+
+  /// The buffer used to accumulate data until the complete WebP header is
+  /// received, if and only if the iterator is discontiguous.
+  Vector<uint8_t> mBufferedData;
+
+  /// The libwebp output buffer descriptor pointing to the decoded data.
+  WebPDecBuffer mBuffer;
+
+  /// The libwebp incremental decoder descriptor, wraps mBuffer.
+  WebPIDecoder* mDecoder;
+
+  /// Blend method for the current frame.
+  BlendMethod mBlend;
+
+  /// Disposal method for the current frame.
+  DisposalMethod mDisposal;
+
+  /// Frame timeout for the current frame;
+  FrameTimeout mTimeout;
+
+  /// Surface format for the current frame.
+  gfx::SurfaceFormat mFormat;
+
+  /// Frame rect for the current frame.
+  OrientedIntRect mFrameRect;
+
+  /// The last row of decoded pixels written to mPipe.
+  int mLastRow;
+
+  /// Number of decoded frames.
+  uint32_t mCurrentFrame;
+
+  /// Pointer to the start of the contiguous encoded image data.
+  const uint8_t* mData;
+
+  /// Length of data pointed to by mData.
+  size_t mLength;
+
+  /// True if the iterator has reached its end.
+  bool mIteratorComplete;
+
+  /// True if this decoding pass requires a WebPDemuxer.
+  bool mNeedDemuxer;
+
+  /// True if we have setup the color profile for the image.
+  bool mGotColorProfile;
+};
+
+}  // namespace image
+}  // namespace mozilla
+
+#endif  // mozilla_image_decoders_nsWebPDecoder_h