Adding upstream version 110.0.1.upstream/110.0.1upstream

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

1 files changed, 2056 insertions, 0 deletions

diff --git a/gfx/2d/DrawTargetSkia.cpp b/gfx/2d/DrawTargetSkia.cpp
new file mode 100644
index 0000000000..c900243ec0
--- /dev/null
+++ b/gfx/2d/DrawTargetSkia.cpp
@@ -0,0 +1,2056 @@
+/* -*- 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 "DrawTargetSkia.h"
+#include "SourceSurfaceSkia.h"
+#include "ScaledFontBase.h"
+#include "FilterNodeSoftware.h"
+#include "HelpersSkia.h"
+
+#include "mozilla/CheckedInt.h"
+#include "mozilla/Vector.h"
+
+#include "skia/include/core/SkCanvas.h"
+#include "skia/include/core/SkFont.h"
+#include "skia/include/core/SkSurface.h"
+#include "skia/include/core/SkTextBlob.h"
+#include "skia/include/core/SkTypeface.h"
+#include "skia/include/effects/SkGradientShader.h"
+#include "skia/include/core/SkColorFilter.h"
+#include "skia/include/core/SkRegion.h"
+#include "skia/include/effects/SkBlurImageFilter.h"
+#include "Blur.h"
+#include "Logging.h"
+#include "Tools.h"
+#include "PathHelpers.h"
+#include "PathSkia.h"
+#include "Swizzle.h"
+#include <algorithm>
+
+#ifdef MOZ_WIDGET_COCOA
+#  include "BorrowedContext.h"
+#  include <ApplicationServices/ApplicationServices.h>
+#endif
+
+#ifdef XP_WIN
+#  include "ScaledFontDWrite.h"
+#endif
+
+namespace mozilla {
+
+void RefPtrTraits<SkSurface>::Release(SkSurface* aSurface) {
+  SkSafeUnref(aSurface);
+}
+
+void RefPtrTraits<SkSurface>::AddRef(SkSurface* aSurface) {
+  SkSafeRef(aSurface);
+}
+
+}  // namespace mozilla
+
+namespace mozilla::gfx {
+
+class GradientStopsSkia : public GradientStops {
+ public:
+  MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(GradientStopsSkia, override)
+
+  GradientStopsSkia(const std::vector<GradientStop>& aStops, uint32_t aNumStops,
+                    ExtendMode aExtendMode)
+      : mCount(aNumStops), mExtendMode(aExtendMode) {
+    if (mCount == 0) {
+      return;
+    }
+
+    // Skia gradients always require a stop at 0.0 and 1.0, insert these if
+    // we don't have them.
+    uint32_t shift = 0;
+    if (aStops[0].offset != 0) {
+      mCount++;
+      shift = 1;
+    }
+    if (aStops[aNumStops - 1].offset != 1) {
+      mCount++;
+    }
+    mColors.resize(mCount);
+    mPositions.resize(mCount);
+    if (aStops[0].offset != 0) {
+      mColors[0] = ColorToSkColor(aStops[0].color, 1.0);
+      mPositions[0] = 0;
+    }
+    for (uint32_t i = 0; i < aNumStops; i++) {
+      mColors[i + shift] = ColorToSkColor(aStops[i].color, 1.0);
+      mPositions[i + shift] = SkFloatToScalar(aStops[i].offset);
+    }
+    if (aStops[aNumStops - 1].offset != 1) {
+      mColors[mCount - 1] = ColorToSkColor(aStops[aNumStops - 1].color, 1.0);
+      mPositions[mCount - 1] = SK_Scalar1;
+    }
+  }
+
+  BackendType GetBackendType() const override { return BackendType::SKIA; }
+
+  std::vector<SkColor> mColors;
+  std::vector<SkScalar> mPositions;
+  int mCount;
+  ExtendMode mExtendMode;
+};
+
+/**
+ * When constructing a temporary SkImage via GetSkImageForSurface, we may also
+ * have to construct a temporary DataSourceSurface, which must live as long as
+ * the SkImage. We attach this temporary surface to the image's pixelref, so
+ * that it can be released once the pixelref is freed.
+ */
+static void ReleaseTemporarySurface(const void* aPixels, void* aContext) {
+  DataSourceSurface* surf = static_cast<DataSourceSurface*>(aContext);
+  if (surf) {
+    surf->Release();
+  }
+}
+
+static void ReleaseTemporaryMappedSurface(const void* aPixels, void* aContext) {
+  DataSourceSurface* surf = static_cast<DataSourceSurface*>(aContext);
+  if (surf) {
+    surf->Unmap();
+    surf->Release();
+  }
+}
+
+static void WriteRGBXFormat(uint8_t* aData, const IntSize& aSize,
+                            const int32_t aStride, SurfaceFormat aFormat) {
+  if (aFormat != SurfaceFormat::B8G8R8X8 || aSize.IsEmpty()) {
+    return;
+  }
+
+  SwizzleData(aData, aStride, SurfaceFormat::X8R8G8B8_UINT32, aData, aStride,
+              SurfaceFormat::A8R8G8B8_UINT32, aSize);
+}
+
+#ifdef DEBUG
+static IntRect CalculateSurfaceBounds(const IntSize& aSize, const Rect* aBounds,
+                                      const Matrix* aMatrix) {
+  IntRect surfaceBounds(IntPoint(0, 0), aSize);
+  if (!aBounds) {
+    return surfaceBounds;
+  }
+
+  MOZ_ASSERT(aMatrix);
+  Matrix inverse(*aMatrix);
+  if (!inverse.Invert()) {
+    return surfaceBounds;
+  }
+
+  IntRect bounds;
+  Rect sampledBounds = inverse.TransformBounds(*aBounds);
+  if (!sampledBounds.ToIntRect(&bounds)) {
+    return surfaceBounds;
+  }
+
+  return surfaceBounds.Intersect(bounds);
+}
+
+static const int kARGBAlphaOffset =
+    SurfaceFormat::A8R8G8B8_UINT32 == SurfaceFormat::B8G8R8A8 ? 3 : 0;
+
+static bool VerifyRGBXFormat(uint8_t* aData, const IntSize& aSize,
+                             const int32_t aStride, SurfaceFormat aFormat) {
+  if (aFormat != SurfaceFormat::B8G8R8X8 || aSize.IsEmpty()) {
+    return true;
+  }
+  // We should've initialized the data to be opaque already
+  // On debug builds, verify that this is actually true.
+  int height = aSize.height;
+  int width = aSize.width * 4;
+
+  for (int row = 0; row < height; ++row) {
+    for (int column = 0; column < width; column += 4) {
+      if (aData[column + kARGBAlphaOffset] != 0xFF) {
+        gfxCriticalError() << "RGBX pixel at (" << column << "," << row
+                           << ") in " << width << "x" << height
+                           << " surface is not opaque: " << int(aData[column])
+                           << "," << int(aData[column + 1]) << ","
+                           << int(aData[column + 2]) << ","
+                           << int(aData[column + 3]);
+      }
+    }
+    aData += aStride;
+  }
+
+  return true;
+}
+
+// Since checking every pixel is expensive, this only checks the four corners
+// and center of a surface that their alpha value is 0xFF.
+static bool VerifyRGBXCorners(uint8_t* aData, const IntSize& aSize,
+                              const int32_t aStride, SurfaceFormat aFormat,
+                              const Rect* aBounds = nullptr,
+                              const Matrix* aMatrix = nullptr) {
+  if (aFormat != SurfaceFormat::B8G8R8X8 || aSize.IsEmpty()) {
+    return true;
+  }
+
+  IntRect bounds = CalculateSurfaceBounds(aSize, aBounds, aMatrix);
+  if (bounds.IsEmpty()) {
+    return true;
+  }
+
+  const int height = bounds.Height();
+  const int width = bounds.Width();
+  const int pixelSize = 4;
+  MOZ_ASSERT(aSize.width * pixelSize <= aStride);
+
+  const int translation = bounds.Y() * aStride + bounds.X() * pixelSize;
+  const int topLeft = translation;
+  const int topRight = topLeft + (width - 1) * pixelSize;
+  const int bottomLeft = translation + (height - 1) * aStride;
+  const int bottomRight = bottomLeft + (width - 1) * pixelSize;
+
+  // Lastly the center pixel
+  const int middleRowHeight = height / 2;
+  const int middleRowWidth = (width / 2) * pixelSize;
+  const int middle = translation + aStride * middleRowHeight + middleRowWidth;
+
+  const int offsets[] = {topLeft, topRight, bottomRight, bottomLeft, middle};
+  for (int offset : offsets) {
+    if (aData[offset + kARGBAlphaOffset] != 0xFF) {
+      int row = offset / aStride;
+      int column = (offset % aStride) / pixelSize;
+      gfxCriticalError() << "RGBX corner pixel at (" << column << "," << row
+                         << ") in " << aSize.width << "x" << aSize.height
+                         << " surface, bounded by "
+                         << "(" << bounds.X() << "," << bounds.Y() << ","
+                         << width << "," << height
+                         << ") is not opaque: " << int(aData[offset]) << ","
+                         << int(aData[offset + 1]) << ","
+                         << int(aData[offset + 2]) << ","
+                         << int(aData[offset + 3]);
+    }
+  }
+
+  return true;
+}
+#endif
+
+static sk_sp<SkImage> GetSkImageForSurface(SourceSurface* aSurface,
+                                           Maybe<MutexAutoLock>* aLock,
+                                           const Rect* aBounds = nullptr,
+                                           const Matrix* aMatrix = nullptr) {
+  if (!aSurface) {
+    gfxDebug() << "Creating null Skia image from null SourceSurface";
+    return nullptr;
+  }
+
+  if (aSurface->GetType() == SurfaceType::SKIA) {
+    return static_cast<SourceSurfaceSkia*>(aSurface)->GetImage(aLock);
+  }
+
+  RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
+  if (!dataSurface) {
+    gfxWarning() << "Failed getting DataSourceSurface for Skia image";
+    return nullptr;
+  }
+
+  DataSourceSurface::MappedSurface map;
+  SkImage::RasterReleaseProc releaseProc;
+  if (dataSurface->GetType() == SurfaceType::DATA_SHARED_WRAPPER) {
+    // Technically all surfaces should be mapped and unmapped explicitly but it
+    // appears SourceSurfaceSkia and DataSourceSurfaceWrapper have issues with
+    // this. For now, we just map SourceSurfaceSharedDataWrapper to ensure we
+    // don't unmap the data during the transaction (for blob images).
+    if (!dataSurface->Map(DataSourceSurface::MapType::READ, &map)) {
+      gfxWarning() << "Failed mapping DataSourceSurface for Skia image";
+      return nullptr;
+    }
+    releaseProc = ReleaseTemporaryMappedSurface;
+  } else {
+    map.mData = dataSurface->GetData();
+    map.mStride = dataSurface->Stride();
+    releaseProc = ReleaseTemporarySurface;
+  }
+
+  DataSourceSurface* surf = dataSurface.forget().take();
+
+  // Skia doesn't support RGBX surfaces so ensure that the alpha value is opaque
+  // white.
+  MOZ_ASSERT(VerifyRGBXCorners(map.mData, surf->GetSize(), map.mStride,
+                               surf->GetFormat(), aBounds, aMatrix));
+
+  SkPixmap pixmap(MakeSkiaImageInfo(surf->GetSize(), surf->GetFormat()),
+                  map.mData, map.mStride);
+  sk_sp<SkImage> image = SkImage::MakeFromRaster(pixmap, releaseProc, surf);
+  if (!image) {
+    releaseProc(map.mData, surf);
+    gfxDebug() << "Failed making Skia raster image for temporary surface";
+  }
+
+  return image;
+}
+
+DrawTargetSkia::DrawTargetSkia()
+    : mCanvas(nullptr),
+      mSnapshot(nullptr),
+      mSnapshotLock{"DrawTargetSkia::mSnapshotLock"}
+#ifdef MOZ_WIDGET_COCOA
+      ,
+      mCG(nullptr),
+      mColorSpace(nullptr),
+      mCanvasData(nullptr),
+      mCGSize(0, 0),
+      mNeedLayer(false)
+#endif
+{
+}
+
+DrawTargetSkia::~DrawTargetSkia() {
+  if (mSnapshot) {
+    MutexAutoLock lock(mSnapshotLock);
+    // We're going to go away, hand our SkSurface to the SourceSurface.
+    mSnapshot->GiveSurface(mSurface.forget().take());
+  }
+
+#ifdef MOZ_WIDGET_COCOA
+  if (mCG) {
+    CGContextRelease(mCG);
+    mCG = nullptr;
+  }
+
+  if (mColorSpace) {
+    CGColorSpaceRelease(mColorSpace);
+    mColorSpace = nullptr;
+  }
+#endif
+}
+
+already_AddRefed<SourceSurface> DrawTargetSkia::Snapshot(
+    SurfaceFormat aFormat) {
+  // Without this lock, this could cause us to get out a snapshot and race with
+  // Snapshot::~Snapshot() actually destroying itself.
+  MutexAutoLock lock(mSnapshotLock);
+  if (mSnapshot && aFormat != mSnapshot->GetFormat()) {
+    if (!mSnapshot->hasOneRef()) {
+      mSnapshot->DrawTargetWillChange();
+    }
+    mSnapshot = nullptr;
+  }
+  RefPtr<SourceSurfaceSkia> snapshot = mSnapshot;
+  if (mSurface && !snapshot) {
+    snapshot = new SourceSurfaceSkia();
+    sk_sp<SkImage> image;
+    // If the surface is raster, making a snapshot may trigger a pixel copy.
+    // Instead, try to directly make a raster image referencing the surface
+    // pixels.
+    SkPixmap pixmap;
+    if (mSurface->peekPixels(&pixmap)) {
+      image = SkImage::MakeFromRaster(pixmap, nullptr, nullptr);
+    } else {
+      image = mSurface->makeImageSnapshot();
+    }
+    if (!snapshot->InitFromImage(image, aFormat, this)) {
+      return nullptr;
+    }
+    mSnapshot = snapshot;
+  }
+
+  return snapshot.forget();
+}
+
+already_AddRefed<SourceSurface> DrawTargetSkia::GetBackingSurface() {
+  if (mBackingSurface) {
+    RefPtr<SourceSurface> snapshot = mBackingSurface;
+    return snapshot.forget();
+  }
+  return Snapshot();
+}
+
+bool DrawTargetSkia::LockBits(uint8_t** aData, IntSize* aSize, int32_t* aStride,
+                              SurfaceFormat* aFormat, IntPoint* aOrigin) {
+  SkImageInfo info;
+  size_t rowBytes;
+  SkIPoint origin;
+  void* pixels = mCanvas->accessTopLayerPixels(&info, &rowBytes, &origin);
+  if (!pixels ||
+      // Ensure the layer is at the origin if required.
+      (!aOrigin && !origin.isZero())) {
+    return false;
+  }
+
+  MarkChanged();
+
+  *aData = reinterpret_cast<uint8_t*>(pixels);
+  *aSize = IntSize(info.width(), info.height());
+  *aStride = int32_t(rowBytes);
+  *aFormat = SkiaColorTypeToGfxFormat(info.colorType(), info.alphaType());
+  if (aOrigin) {
+    *aOrigin = IntPoint(origin.x(), origin.y());
+  }
+  return true;
+}
+
+void DrawTargetSkia::ReleaseBits(uint8_t* aData) {}
+
+static void ReleaseImage(const void* aPixels, void* aContext) {
+  SkImage* image = static_cast<SkImage*>(aContext);
+  SkSafeUnref(image);
+}
+
+static sk_sp<SkImage> ExtractSubset(sk_sp<SkImage> aImage,
+                                    const IntRect& aRect) {
+  SkIRect subsetRect = IntRectToSkIRect(aRect);
+  if (aImage->bounds() == subsetRect) {
+    return aImage;
+  }
+  // makeSubset is slow, so prefer to use SkPixmap::extractSubset where
+  // possible.
+  SkPixmap pixmap, subsetPixmap;
+  if (aImage->peekPixels(&pixmap) &&
+      pixmap.extractSubset(&subsetPixmap, subsetRect)) {
+    // Release the original image reference so only the subset image keeps it
+    // alive.
+    return SkImage::MakeFromRaster(subsetPixmap, ReleaseImage,
+                                   aImage.release());
+  }
+  return aImage->makeSubset(subsetRect);
+}
+
+static void FreeAlphaPixels(void* aBuf, void*) { sk_free(aBuf); }
+
+static bool ExtractAlphaBitmap(const sk_sp<SkImage>& aImage,
+                               SkBitmap* aResultBitmap,
+                               bool aAllowReuse = false) {
+  SkPixmap pixmap;
+  if (aAllowReuse && aImage->isAlphaOnly() && aImage->peekPixels(&pixmap)) {
+    SkBitmap bitmap;
+    bitmap.installPixels(pixmap.info(), pixmap.writable_addr(),
+                         pixmap.rowBytes());
+    *aResultBitmap = bitmap;
+    return true;
+  }
+  SkImageInfo info = SkImageInfo::MakeA8(aImage->width(), aImage->height());
+  // Skia does not fully allocate the last row according to stride.
+  // Since some of our algorithms (i.e. blur) depend on this, we must allocate
+  // the bitmap pixels manually.
+  size_t stride = SkAlign4(info.minRowBytes());
+  CheckedInt<size_t> size = stride;
+  size *= info.height();
+  // We need to leave room for an additional 3 bytes for a potential overrun
+  // in our blurring code.
+  size += 3;
+  if (size.isValid()) {
+    void* buf = sk_malloc_flags(size.value(), 0);
+    if (buf) {
+      SkBitmap bitmap;
+      if (bitmap.installPixels(info, buf, stride, FreeAlphaPixels, nullptr) &&
+          aImage->readPixels(bitmap.info(), bitmap.getPixels(),
+                             bitmap.rowBytes(), 0, 0)) {
+        *aResultBitmap = bitmap;
+        return true;
+      }
+    }
+  }
+
+  gfxWarning() << "Failed reading alpha pixels for Skia bitmap";
+  return false;
+}
+
+static sk_sp<SkImage> ExtractAlphaForSurface(SourceSurface* aSurface,
+                                             Maybe<MutexAutoLock>& aLock) {
+  sk_sp<SkImage> image = GetSkImageForSurface(aSurface, &aLock);
+  if (!image) {
+    return nullptr;
+  }
+  if (image->isAlphaOnly()) {
+    return image;
+  }
+
+  SkBitmap bitmap;
+  if (!ExtractAlphaBitmap(image, &bitmap)) {
+    return nullptr;
+  }
+
+  // Mark the bitmap immutable so that it will be shared rather than copied.
+  bitmap.setImmutable();
+  return SkImage::MakeFromBitmap(bitmap);
+}
+
+static void SetPaintPattern(SkPaint& aPaint, const Pattern& aPattern,
+                            Maybe<MutexAutoLock>& aLock, Float aAlpha = 1.0,
+                            const SkMatrix* aMatrix = nullptr,
+                            const Rect* aBounds = nullptr) {
+  switch (aPattern.GetType()) {
+    case PatternType::COLOR: {
+      DeviceColor color = static_cast<const ColorPattern&>(aPattern).mColor;
+      aPaint.setColor(ColorToSkColor(color, aAlpha));
+      break;
+    }
+    case PatternType::LINEAR_GRADIENT: {
+      const LinearGradientPattern& pat =
+          static_cast<const LinearGradientPattern&>(aPattern);
+      GradientStopsSkia* stops =
+          static_cast<GradientStopsSkia*>(pat.mStops.get());
+      if (!stops || stops->mCount < 2 || !pat.mBegin.IsFinite() ||
+          !pat.mEnd.IsFinite() || pat.mBegin == pat.mEnd) {
+        aPaint.setColor(SK_ColorTRANSPARENT);
+      } else {
+        SkTileMode mode = ExtendModeToTileMode(stops->mExtendMode, Axis::BOTH);
+        SkPoint points[2];
+        points[0] = SkPoint::Make(SkFloatToScalar(pat.mBegin.x),
+                                  SkFloatToScalar(pat.mBegin.y));
+        points[1] = SkPoint::Make(SkFloatToScalar(pat.mEnd.x),
+                                  SkFloatToScalar(pat.mEnd.y));
+
+        SkMatrix mat;
+        GfxMatrixToSkiaMatrix(pat.mMatrix, mat);
+        if (aMatrix) {
+          mat.postConcat(*aMatrix);
+        }
+        sk_sp<SkShader> shader = SkGradientShader::MakeLinear(
+            points, &stops->mColors.front(), &stops->mPositions.front(),
+            stops->mCount, mode, 0, &mat);
+        if (shader) {
+          aPaint.setShader(shader);
+        } else {
+          aPaint.setColor(SK_ColorTRANSPARENT);
+        }
+      }
+      break;
+    }
+    case PatternType::RADIAL_GRADIENT: {
+      const RadialGradientPattern& pat =
+          static_cast<const RadialGradientPattern&>(aPattern);
+      GradientStopsSkia* stops =
+          static_cast<GradientStopsSkia*>(pat.mStops.get());
+      if (!stops || stops->mCount < 2 || !pat.mCenter1.IsFinite() ||
+          !IsFinite(pat.mRadius1) || !pat.mCenter2.IsFinite() ||
+          !IsFinite(pat.mRadius2) ||
+          (pat.mCenter1 == pat.mCenter2 && pat.mRadius1 == pat.mRadius2)) {
+        aPaint.setColor(SK_ColorTRANSPARENT);
+      } else {
+        SkTileMode mode = ExtendModeToTileMode(stops->mExtendMode, Axis::BOTH);
+        SkPoint points[2];
+        points[0] = SkPoint::Make(SkFloatToScalar(pat.mCenter1.x),
+                                  SkFloatToScalar(pat.mCenter1.y));
+        points[1] = SkPoint::Make(SkFloatToScalar(pat.mCenter2.x),
+                                  SkFloatToScalar(pat.mCenter2.y));
+
+        SkMatrix mat;
+        GfxMatrixToSkiaMatrix(pat.mMatrix, mat);
+        if (aMatrix) {
+          mat.postConcat(*aMatrix);
+        }
+        sk_sp<SkShader> shader = SkGradientShader::MakeTwoPointConical(
+            points[0], SkFloatToScalar(pat.mRadius1), points[1],
+            SkFloatToScalar(pat.mRadius2), &stops->mColors.front(),
+            &stops->mPositions.front(), stops->mCount, mode, 0, &mat);
+        if (shader) {
+          aPaint.setShader(shader);
+        } else {
+          aPaint.setColor(SK_ColorTRANSPARENT);
+        }
+      }
+      break;
+    }
+    case PatternType::CONIC_GRADIENT: {
+      const ConicGradientPattern& pat =
+          static_cast<const ConicGradientPattern&>(aPattern);
+      GradientStopsSkia* stops =
+          static_cast<GradientStopsSkia*>(pat.mStops.get());
+      if (!stops || stops->mCount < 2 || !pat.mCenter.IsFinite() ||
+          !IsFinite(pat.mAngle)) {
+        aPaint.setColor(SK_ColorTRANSPARENT);
+      } else {
+        SkMatrix mat;
+        GfxMatrixToSkiaMatrix(pat.mMatrix, mat);
+        if (aMatrix) {
+          mat.postConcat(*aMatrix);
+        }
+
+        SkScalar cx = SkFloatToScalar(pat.mCenter.x);
+        SkScalar cy = SkFloatToScalar(pat.mCenter.y);
+
+        // Skia's sweep gradient angles are relative to the x-axis, not the
+        // y-axis.
+        Float angle = (pat.mAngle * 180.0 / M_PI) - 90.0;
+        if (angle != 0.0) {
+          mat.preRotate(angle, cx, cy);
+        }
+
+        SkTileMode mode = ExtendModeToTileMode(stops->mExtendMode, Axis::BOTH);
+        sk_sp<SkShader> shader = SkGradientShader::MakeSweep(
+            cx, cy, &stops->mColors.front(), &stops->mPositions.front(),
+            stops->mCount, mode, 360 * pat.mStartOffset, 360 * pat.mEndOffset,
+            0, &mat);
+
+        if (shader) {
+          aPaint.setShader(shader);
+        } else {
+          aPaint.setColor(SK_ColorTRANSPARENT);
+        }
+      }
+      break;
+    }
+    case PatternType::SURFACE: {
+      const SurfacePattern& pat = static_cast<const SurfacePattern&>(aPattern);
+      sk_sp<SkImage> image =
+          GetSkImageForSurface(pat.mSurface, &aLock, aBounds, &pat.mMatrix);
+      if (!image) {
+        aPaint.setColor(SK_ColorTRANSPARENT);
+        break;
+      }
+
+      SkMatrix mat;
+      GfxMatrixToSkiaMatrix(pat.mMatrix, mat);
+      if (aMatrix) {
+        mat.postConcat(*aMatrix);
+      }
+
+      if (!pat.mSamplingRect.IsEmpty()) {
+        image = ExtractSubset(image, pat.mSamplingRect);
+        if (!image) {
+          aPaint.setColor(SK_ColorTRANSPARENT);
+          break;
+        }
+        mat.preTranslate(pat.mSamplingRect.X(), pat.mSamplingRect.Y());
+      }
+
+      SkTileMode xTile = ExtendModeToTileMode(pat.mExtendMode, Axis::X_AXIS);
+      SkTileMode yTile = ExtendModeToTileMode(pat.mExtendMode, Axis::Y_AXIS);
+
+      sk_sp<SkShader> shader = image->makeShader(xTile, yTile, &mat);
+      if (shader) {
+        aPaint.setShader(shader);
+      } else {
+        gfxDebug() << "Failed creating Skia surface shader: x-tile="
+                   << (int)xTile << " y-tile=" << (int)yTile
+                   << " matrix=" << (mat.isFinite() ? "finite" : "non-finite");
+        aPaint.setColor(SK_ColorTRANSPARENT);
+      }
+
+      if (pat.mSamplingFilter == SamplingFilter::POINT) {
+        aPaint.setFilterQuality(kNone_SkFilterQuality);
+      }
+      break;
+    }
+  }
+}
+
+static inline Rect GetClipBounds(SkCanvas* aCanvas) {
+  // Use a manually transformed getClipDeviceBounds instead of
+  // getClipBounds because getClipBounds inflates the the bounds
+  // by a pixel in each direction to compensate for antialiasing.
+  SkIRect deviceBounds;
+  if (!aCanvas->getDeviceClipBounds(&deviceBounds)) {
+    return Rect();
+  }
+  SkMatrix inverseCTM;
+  if (!aCanvas->getTotalMatrix().invert(&inverseCTM)) {
+    return Rect();
+  }
+  SkRect localBounds;
+  inverseCTM.mapRect(&localBounds, SkRect::Make(deviceBounds));
+  return SkRectToRect(localBounds);
+}
+
+struct AutoPaintSetup {
+  AutoPaintSetup(SkCanvas* aCanvas, const DrawOptions& aOptions,
+                 const Pattern& aPattern, const Rect* aMaskBounds = nullptr,
+                 const SkMatrix* aMatrix = nullptr,
+                 const Rect* aSourceBounds = nullptr)
+      : mNeedsRestore(false), mAlpha(1.0) {
+    Init(aCanvas, aOptions, aMaskBounds, false);
+    SetPaintPattern(mPaint, aPattern, mLock, mAlpha, aMatrix, aSourceBounds);
+  }
+
+  AutoPaintSetup(SkCanvas* aCanvas, const DrawOptions& aOptions,
+                 const Rect* aMaskBounds = nullptr, bool aForceGroup = false)
+      : mNeedsRestore(false), mAlpha(1.0) {
+    Init(aCanvas, aOptions, aMaskBounds, aForceGroup);
+  }
+
+  ~AutoPaintSetup() {
+    if (mNeedsRestore) {
+      mCanvas->restore();
+    }
+  }
+
+  void Init(SkCanvas* aCanvas, const DrawOptions& aOptions,
+            const Rect* aMaskBounds, bool aForceGroup) {
+    mPaint.setBlendMode(GfxOpToSkiaOp(aOptions.mCompositionOp));
+    mCanvas = aCanvas;
+
+    // TODO: Can we set greyscale somehow?
+    if (aOptions.mAntialiasMode != AntialiasMode::NONE) {
+      mPaint.setAntiAlias(true);
+    } else {
+      mPaint.setAntiAlias(false);
+    }
+
+    bool needsGroup =
+        aForceGroup ||
+        (!IsOperatorBoundByMask(aOptions.mCompositionOp) &&
+         (!aMaskBounds || !aMaskBounds->Contains(GetClipBounds(aCanvas))));
+
+    // TODO: We could skip the temporary for operator_source and just
+    // clear the clip rect. The other operators would be harder
+    // but could be worth it to skip pushing a group.
+    if (needsGroup) {
+      mPaint.setBlendMode(SkBlendMode::kSrcOver);
+      SkPaint temp;
+      temp.setBlendMode(GfxOpToSkiaOp(aOptions.mCompositionOp));
+      temp.setAlpha(ColorFloatToByte(aOptions.mAlpha));
+      // TODO: Get a rect here
+      SkCanvas::SaveLayerRec rec(nullptr, &temp,
+                                 SkCanvas::kPreserveLCDText_SaveLayerFlag);
+      mCanvas->saveLayer(rec);
+      mNeedsRestore = true;
+    } else {
+      mPaint.setAlpha(ColorFloatToByte(aOptions.mAlpha));
+      mAlpha = aOptions.mAlpha;
+    }
+    mPaint.setFilterQuality(kLow_SkFilterQuality);
+  }
+
+  // TODO: Maybe add an operator overload to access this easier?
+  SkPaint mPaint;
+  bool mNeedsRestore;
+  SkCanvas* mCanvas;
+  Maybe<MutexAutoLock> mLock;
+  Float mAlpha;
+};
+
+void DrawTargetSkia::Flush() { mCanvas->flush(); }
+
+void DrawTargetSkia::DrawSurface(SourceSurface* aSurface, const Rect& aDest,
+                                 const Rect& aSource,
+                                 const DrawSurfaceOptions& aSurfOptions,
+                                 const DrawOptions& aOptions) {
+  if (aSource.IsEmpty()) {
+    return;
+  }
+
+  MarkChanged();
+
+  Maybe<MutexAutoLock> lock;
+  sk_sp<SkImage> image = GetSkImageForSurface(aSurface, &lock);
+  if (!image) {
+    return;
+  }
+
+  SkRect destRect = RectToSkRect(aDest);
+  SkRect sourceRect = RectToSkRect(aSource - aSurface->GetRect().TopLeft());
+  bool forceGroup =
+      image->isAlphaOnly() && aOptions.mCompositionOp != CompositionOp::OP_OVER;
+
+  AutoPaintSetup paint(mCanvas, aOptions, &aDest, forceGroup);
+  if (aSurfOptions.mSamplingFilter == SamplingFilter::POINT) {
+    paint.mPaint.setFilterQuality(kNone_SkFilterQuality);
+  }
+
+  mCanvas->drawImageRect(image, sourceRect, destRect, &paint.mPaint);
+}
+
+DrawTargetType DrawTargetSkia::GetType() const {
+  return DrawTargetType::SOFTWARE_RASTER;
+}
+
+void DrawTargetSkia::DrawFilter(FilterNode* aNode, const Rect& aSourceRect,
+                                const Point& aDestPoint,
+                                const DrawOptions& aOptions) {
+  FilterNodeSoftware* filter = static_cast<FilterNodeSoftware*>(aNode);
+  filter->Draw(this, aSourceRect, aDestPoint, aOptions);
+}
+
+void DrawTargetSkia::DrawSurfaceWithShadow(SourceSurface* aSurface,
+                                           const Point& aDest,
+                                           const ShadowOptions& aShadow,
+                                           CompositionOp aOperator) {
+  if (aSurface->GetSize().IsEmpty()) {
+    return;
+  }
+
+  MarkChanged();
+
+  Maybe<MutexAutoLock> lock;
+  sk_sp<SkImage> image = GetSkImageForSurface(aSurface, &lock);
+  if (!image) {
+    return;
+  }
+
+  mCanvas->save();
+  mCanvas->resetMatrix();
+
+  SkPaint paint;
+  paint.setBlendMode(GfxOpToSkiaOp(aOperator));
+
+  // bug 1201272
+  // We can't use the SkDropShadowImageFilter here because it applies the xfer
+  // mode first to render the bitmap to a temporary layer, and then implicitly
+  // uses src-over to composite the resulting shadow.
+  // The canvas spec, however, states that the composite op must be used to
+  // composite the resulting shadow, so we must instead use a SkBlurImageFilter
+  // to blur the image ourselves.
+
+  SkPaint shadowPaint;
+  shadowPaint.setBlendMode(GfxOpToSkiaOp(aOperator));
+
+  auto shadowDest = IntPoint::Round(aDest + aShadow.mOffset);
+
+  SkBitmap blurMask;
+  // Extract the alpha channel of the image into a bitmap. If the image is A8
+  // format already, then we can directly reuse the bitmap rather than create a
+  // new one as the surface only needs to be drawn from once.
+  if (ExtractAlphaBitmap(image, &blurMask, true)) {
+    // Prefer using our own box blur instead of Skia's. It currently performs
+    // much better than SkBlurImageFilter or SkBlurMaskFilter on the CPU.
+    AlphaBoxBlur blur(Rect(0, 0, blurMask.width(), blurMask.height()),
+                      int32_t(blurMask.rowBytes()), aShadow.mSigma,
+                      aShadow.mSigma);
+    blur.Blur(reinterpret_cast<uint8_t*>(blurMask.getPixels()));
+    blurMask.notifyPixelsChanged();
+
+    shadowPaint.setColor(ColorToSkColor(aShadow.mColor, 1.0f));
+
+    mCanvas->drawBitmap(blurMask, shadowDest.x, shadowDest.y, &shadowPaint);
+  } else {
+    sk_sp<SkImageFilter> blurFilter(
+        SkBlurImageFilter::Make(aShadow.mSigma, aShadow.mSigma, nullptr));
+    sk_sp<SkColorFilter> colorFilter(SkColorFilters::Blend(
+        ColorToSkColor(aShadow.mColor, 1.0f), SkBlendMode::kSrcIn));
+
+    shadowPaint.setImageFilter(blurFilter);
+    shadowPaint.setColorFilter(colorFilter);
+
+    mCanvas->drawImage(image, shadowDest.x, shadowDest.y, &shadowPaint);
+  }
+
+  if (aSurface->GetFormat() != SurfaceFormat::A8) {
+    // Composite the original image after the shadow
+    auto dest = IntPoint::Round(aDest);
+    mCanvas->drawImage(image, dest.x, dest.y, &paint);
+  }
+
+  mCanvas->restore();
+}
+
+void DrawTargetSkia::FillRect(const Rect& aRect, const Pattern& aPattern,
+                              const DrawOptions& aOptions) {
+  // The sprite blitting path in Skia can be faster than the shader blitter for
+  // operators other than source (or source-over with opaque surface). So, when
+  // possible/beneficial, route to DrawSurface which will use the sprite
+  // blitter.
+  if (aPattern.GetType() == PatternType::SURFACE &&
+      aOptions.mCompositionOp != CompositionOp::OP_SOURCE) {
+    const SurfacePattern& pat = static_cast<const SurfacePattern&>(aPattern);
+    // Verify there is a valid surface and a pattern matrix without skew.
+    if (pat.mSurface &&
+        (aOptions.mCompositionOp != CompositionOp::OP_OVER ||
+         GfxFormatToSkiaAlphaType(pat.mSurface->GetFormat()) !=
+             kOpaque_SkAlphaType) &&
+        !pat.mMatrix.HasNonAxisAlignedTransform()) {
+      // Bound the sampling to smaller of the bounds or the sampling rect.
+      IntRect srcRect(IntPoint(0, 0), pat.mSurface->GetSize());
+      if (!pat.mSamplingRect.IsEmpty()) {
+        srcRect = srcRect.Intersect(pat.mSamplingRect);
+      }
+      // Transform the destination rectangle by the inverse of the pattern
+      // matrix so that it is in pattern space like the source rectangle.
+      Rect patRect = aRect - pat.mMatrix.GetTranslation();
+      patRect.Scale(1.0f / pat.mMatrix._11, 1.0f / pat.mMatrix._22);
+      // Verify the pattern rectangle will not tile or clamp.
+      if (!patRect.IsEmpty() && srcRect.Contains(RoundedOut(patRect))) {
+        // The pattern is a surface with an axis-aligned source rectangle
+        // fitting entirely in its bounds, so just treat it as a DrawSurface.
+        DrawSurface(pat.mSurface, aRect, patRect,
+                    DrawSurfaceOptions(pat.mSamplingFilter), aOptions);
+        return;
+      }
+    }
+  }
+
+  MarkChanged();
+  SkRect rect = RectToSkRect(aRect);
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern, &aRect, nullptr, &aRect);
+
+  mCanvas->drawRect(rect, paint.mPaint);
+}
+
+void DrawTargetSkia::Stroke(const Path* aPath, const Pattern& aPattern,
+                            const StrokeOptions& aStrokeOptions,
+                            const DrawOptions& aOptions) {
+  MarkChanged();
+  MOZ_ASSERT(aPath, "Null path");
+  if (aPath->GetBackendType() != BackendType::SKIA) {
+    return;
+  }
+
+  const PathSkia* skiaPath = static_cast<const PathSkia*>(aPath);
+
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern);
+  if (!StrokeOptionsToPaint(paint.mPaint, aStrokeOptions)) {
+    return;
+  }
+
+  if (!skiaPath->GetPath().isFinite()) {
+    return;
+  }
+
+  mCanvas->drawPath(skiaPath->GetPath(), paint.mPaint);
+}
+
+static Double DashPeriodLength(const StrokeOptions& aStrokeOptions) {
+  Double length = 0;
+  for (size_t i = 0; i < aStrokeOptions.mDashLength; i++) {
+    length += aStrokeOptions.mDashPattern[i];
+  }
+  if (aStrokeOptions.mDashLength & 1) {
+    // "If an odd number of values is provided, then the list of values is
+    // repeated to yield an even number of values."
+    // Double the length.
+    length += length;
+  }
+  return length;
+}
+
+static inline Double RoundDownToMultiple(Double aValue, Double aFactor) {
+  return floor(aValue / aFactor) * aFactor;
+}
+
+static Rect UserSpaceStrokeClip(const IntRect& aDeviceClip,
+                                const Matrix& aTransform,
+                                const StrokeOptions& aStrokeOptions) {
+  Matrix inverse = aTransform;
+  if (!inverse.Invert()) {
+    return Rect();
+  }
+  Rect deviceClip(aDeviceClip);
+  deviceClip.Inflate(MaxStrokeExtents(aStrokeOptions, aTransform));
+  return inverse.TransformBounds(deviceClip);
+}
+
+static Rect ShrinkClippedStrokedRect(const Rect& aStrokedRect,
+                                     const IntRect& aDeviceClip,
+                                     const Matrix& aTransform,
+                                     const StrokeOptions& aStrokeOptions) {
+  Rect userSpaceStrokeClip =
+      UserSpaceStrokeClip(aDeviceClip, aTransform, aStrokeOptions);
+  RectDouble strokedRectDouble(aStrokedRect.X(), aStrokedRect.Y(),
+                               aStrokedRect.Width(), aStrokedRect.Height());
+  RectDouble intersection = strokedRectDouble.Intersect(
+      RectDouble(userSpaceStrokeClip.X(), userSpaceStrokeClip.Y(),
+                 userSpaceStrokeClip.Width(), userSpaceStrokeClip.Height()));
+  Double dashPeriodLength = DashPeriodLength(aStrokeOptions);
+  if (intersection.IsEmpty() || dashPeriodLength == 0.0f) {
+    return Rect(intersection.X(), intersection.Y(), intersection.Width(),
+                intersection.Height());
+  }
+
+  // Reduce the rectangle side lengths in multiples of the dash period length
+  // so that the visible dashes stay in the same place.
+  MarginDouble insetBy = strokedRectDouble - intersection;
+  insetBy.top = RoundDownToMultiple(insetBy.top, dashPeriodLength);
+  insetBy.right = RoundDownToMultiple(insetBy.right, dashPeriodLength);
+  insetBy.bottom = RoundDownToMultiple(insetBy.bottom, dashPeriodLength);
+  insetBy.left = RoundDownToMultiple(insetBy.left, dashPeriodLength);
+
+  strokedRectDouble.Deflate(insetBy);
+  return Rect(strokedRectDouble.X(), strokedRectDouble.Y(),
+              strokedRectDouble.Width(), strokedRectDouble.Height());
+}
+
+void DrawTargetSkia::StrokeRect(const Rect& aRect, const Pattern& aPattern,
+                                const StrokeOptions& aStrokeOptions,
+                                const DrawOptions& aOptions) {
+  // Stroking large rectangles with dashes is expensive with Skia (fixed
+  // overhead based on the number of dashes, regardless of whether the dashes
+  // are visible), so we try to reduce the size of the stroked rectangle as
+  // much as possible before passing it on to Skia.
+  Rect rect = aRect;
+  if (aStrokeOptions.mDashLength > 0 && !rect.IsEmpty()) {
+    IntRect deviceClip(IntPoint(0, 0), mSize);
+    SkIRect clipBounds;
+    if (mCanvas->getDeviceClipBounds(&clipBounds)) {
+      deviceClip = SkIRectToIntRect(clipBounds);
+    }
+    rect =
+        ShrinkClippedStrokedRect(rect, deviceClip, mTransform, aStrokeOptions);
+    if (rect.IsEmpty()) {
+      return;
+    }
+  }
+
+  MarkChanged();
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern);
+  if (!StrokeOptionsToPaint(paint.mPaint, aStrokeOptions)) {
+    return;
+  }
+
+  mCanvas->drawRect(RectToSkRect(rect), paint.mPaint);
+}
+
+void DrawTargetSkia::StrokeLine(const Point& aStart, const Point& aEnd,
+                                const Pattern& aPattern,
+                                const StrokeOptions& aStrokeOptions,
+                                const DrawOptions& aOptions) {
+  MarkChanged();
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern);
+  if (!StrokeOptionsToPaint(paint.mPaint, aStrokeOptions)) {
+    return;
+  }
+
+  mCanvas->drawLine(SkFloatToScalar(aStart.x), SkFloatToScalar(aStart.y),
+                    SkFloatToScalar(aEnd.x), SkFloatToScalar(aEnd.y),
+                    paint.mPaint);
+}
+
+void DrawTargetSkia::Fill(const Path* aPath, const Pattern& aPattern,
+                          const DrawOptions& aOptions) {
+  MarkChanged();
+  if (!aPath || aPath->GetBackendType() != BackendType::SKIA) {
+    return;
+  }
+
+  const PathSkia* skiaPath = static_cast<const PathSkia*>(aPath);
+
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern);
+
+  if (!skiaPath->GetPath().isFinite()) {
+    return;
+  }
+
+  mCanvas->drawPath(skiaPath->GetPath(), paint.mPaint);
+}
+
+#ifdef MOZ_WIDGET_COCOA
+static inline CGAffineTransform GfxMatrixToCGAffineTransform(const Matrix& m) {
+  CGAffineTransform t;
+  t.a = m._11;
+  t.b = m._12;
+  t.c = m._21;
+  t.d = m._22;
+  t.tx = m._31;
+  t.ty = m._32;
+  return t;
+}
+
+/***
+ * We have to do a lot of work to draw glyphs with CG because
+ * CG assumes that the origin of rects are in the bottom left
+ * while every other DrawTarget assumes the top left is the origin.
+ * This means we have to transform the CGContext to have rects
+ * actually be applied in top left fashion. We do this by:
+ *
+ * 1) Translating the context up by the height of the canvas
+ * 2) Flipping the context by the Y axis so it's upside down.
+ *
+ * These two transforms put the origin in the top left.
+ * Transforms are better understood thinking about them from right to left order
+ * (mathematically).
+ *
+ * Consider a point we want to draw at (0, 10) in normal cartesian planes with
+ * a box of (100, 100). in CG terms, this would be at (0, 10).
+ * Positive Y values point up.
+ * In our DrawTarget terms, positive Y values point down, so (0, 10) would be
+ * at (0, 90) in cartesian plane terms. That means our point at (0, 10) in
+ * DrawTarget terms should end up at (0, 90). How does this work with the
+ * current transforms?
+ *
+ * Going right to left with the transforms, a CGPoint of (0, 10) has cartesian
+ * coordinates of (0, 10). The first flip of the Y axis puts the point now at
+ * (0, -10); Next, we translate the context up by the size of the canvas
+ * (Positive Y values go up in CG coordinates but down in our draw target
+ * coordinates). Since our canvas size is (100, 100), the resulting coordinate
+ * becomes (0, 90), which is what we expect from our DrawTarget code. These two
+ * transforms put the CG context equal to what every other DrawTarget expects.
+ *
+ * Next, we need two more transforms for actual text. IF we left the transforms
+ * as is, the text would be drawn upside down, so we need another flip of the Y
+ * axis to draw the text right side up. However, with only the flip, the text
+ * would be drawn in the wrong place. Thus we also have to invert the Y position
+ * of the glyphs to get them in the right place.
+ *
+ * Thus we have the following transforms:
+ * 1) Translation of the context up
+ * 2) Flipping the context around the Y axis
+ * 3) Flipping the context around the Y axis
+ * 4) Inverting the Y position of each glyph
+ *
+ * We cannot cancel out (2) and (3) as we have to apply the clips and transforms
+ * of DrawTargetSkia between (2) and (3).
+ *
+ * Consider the example letter P, drawn at (0, 20) in CG coordinates in a
+ * (100, 100) rect.
+ * Again, going right to left of the transforms. We'd get:
+ *
+ * 1) The letter P drawn at (0, -20) due to the inversion of the Y axis
+ * 2) The letter P upside down (b) at (0, 20) due to the second flip
+ * 3) The letter P right side up at (0, -20) due to the first flip
+ * 4) The letter P right side up at (0, 80) due to the translation
+ *
+ * tl;dr - CGRects assume origin is bottom left, DrawTarget rects assume top
+ * left.
+ */
+static bool SetupCGContext(DrawTargetSkia* aDT, CGContextRef aCGContext,
+                           SkCanvas* aCanvas, const IntPoint& aOrigin,
+                           const IntSize& aSize, bool aClipped) {
+  // DrawTarget expects the origin to be at the top left, but CG
+  // expects it to be at the bottom left. Transform to set the origin to
+  // the top left. Have to set this before we do anything else.
+  // This is transform (1) up top
+  CGContextTranslateCTM(aCGContext, -aOrigin.x, aOrigin.y + aSize.height);
+
+  // Transform (2) from the comments.
+  CGContextScaleCTM(aCGContext, 1, -1);
+
+  // Want to apply clips BEFORE the transform since the transform
+  // will apply to the clips we apply.
+  if (aClipped) {
+    SkRegion clipRegion;
+    aCanvas->temporary_internal_getRgnClip(&clipRegion);
+    Vector<CGRect, 8> rects;
+    for (SkRegion::Iterator it(clipRegion); !it.done(); it.next()) {
+      const SkIRect& rect = it.rect();
+      if (!rects.append(
+              CGRectMake(rect.x(), rect.y(), rect.width(), rect.height()))) {
+        break;
+      }
+    }
+    if (rects.length()) {
+      CGContextClipToRects(aCGContext, rects.begin(), rects.length());
+    }
+  }
+
+  CGContextConcatCTM(aCGContext,
+                     GfxMatrixToCGAffineTransform(aDT->GetTransform()));
+  return true;
+}
+// End long comment about transforms.
+
+// The context returned from this method will have the origin
+// in the top left and will have applied all the neccessary clips
+// and transforms to the CGContext. See the comment above
+// SetupCGContext.
+CGContextRef DrawTargetSkia::BorrowCGContext(const DrawOptions& aOptions) {
+  // Since we can't replay Skia clips, we have to use a layer if we have a
+  // complex clip. After saving a layer, the SkCanvas queries for needing a
+  // layer change so save if we pushed a layer.
+  mNeedLayer = !mCanvas->isClipEmpty() && !mCanvas->isClipRect();
+  if (mNeedLayer) {
+    SkPaint paint;
+    paint.setBlendMode(SkBlendMode::kSrc);
+    SkCanvas::SaveLayerRec rec(nullptr, &paint,
+                               SkCanvas::kInitWithPrevious_SaveLayerFlag);
+    mCanvas->saveLayer(rec);
+  }
+
+  uint8_t* data = nullptr;
+  int32_t stride;
+  SurfaceFormat format;
+  IntSize size;
+  IntPoint origin;
+  if (!LockBits(&data, &size, &stride, &format, &origin)) {
+    NS_WARNING("Could not lock skia bits to wrap CG around");
+    return nullptr;
+  }
+
+  if (!mNeedLayer && (data == mCanvasData) && mCG && (mCGSize == size)) {
+    // If our canvas data still points to the same data,
+    // we can reuse the CG Context
+    CGContextSetAlpha(mCG, aOptions.mAlpha);
+    CGContextSetShouldAntialias(mCG,
+                                aOptions.mAntialiasMode != AntialiasMode::NONE);
+    CGContextSaveGState(mCG);
+    SetupCGContext(this, mCG, mCanvas, origin, size, true);
+    return mCG;
+  }
+
+  if (!mColorSpace) {
+    mColorSpace = (format == SurfaceFormat::A8) ? CGColorSpaceCreateDeviceGray()
+                                                : CGColorSpaceCreateDeviceRGB();
+  }
+
+  if (mCG) {
+    // Release the old CG context since it's no longer valid.
+    CGContextRelease(mCG);
+  }
+
+  mCanvasData = data;
+  mCGSize = size;
+
+  uint32_t bitmapInfo =
+      (format == SurfaceFormat::A8)
+          ? kCGImageAlphaOnly
+          : kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host;
+
+  mCG = CGBitmapContextCreateWithData(
+      mCanvasData, mCGSize.width, mCGSize.height, 8, /* bits per component */
+      stride, mColorSpace, bitmapInfo, NULL, /* Callback when released */
+      NULL);
+  if (!mCG) {
+    if (mNeedLayer) {
+      mCanvas->restore();
+    }
+    ReleaseBits(mCanvasData);
+    NS_WARNING("Could not create bitmap around skia data\n");
+    return nullptr;
+  }
+
+  CGContextSetAlpha(mCG, aOptions.mAlpha);
+  CGContextSetShouldAntialias(mCG,
+                              aOptions.mAntialiasMode != AntialiasMode::NONE);
+  CGContextSetShouldSmoothFonts(mCG, true);
+  CGContextSetTextDrawingMode(mCG, kCGTextFill);
+  CGContextSaveGState(mCG);
+  SetupCGContext(this, mCG, mCanvas, origin, size, !mNeedLayer);
+  return mCG;
+}
+
+void DrawTargetSkia::ReturnCGContext(CGContextRef aCGContext) {
+  MOZ_ASSERT(aCGContext == mCG);
+  ReleaseBits(mCanvasData);
+  CGContextRestoreGState(aCGContext);
+
+  if (mNeedLayer) {
+    // A layer was used for clipping and is about to be popped by the restore.
+    // Make sure the CG context referencing it is released first so the popped
+    // layer doesn't accidentally get used.
+    if (mCG) {
+      CGContextRelease(mCG);
+      mCG = nullptr;
+    }
+    mCanvas->restore();
+  }
+}
+
+CGContextRef BorrowedCGContext::BorrowCGContextFromDrawTarget(DrawTarget* aDT) {
+  DrawTargetSkia* skiaDT = static_cast<DrawTargetSkia*>(aDT);
+  return skiaDT->BorrowCGContext(DrawOptions());
+}
+
+void BorrowedCGContext::ReturnCGContextToDrawTarget(DrawTarget* aDT,
+                                                    CGContextRef cg) {
+  DrawTargetSkia* skiaDT = static_cast<DrawTargetSkia*>(aDT);
+  skiaDT->ReturnCGContext(cg);
+}
+#endif
+
+static bool CanDrawFont(ScaledFont* aFont) {
+  switch (aFont->GetType()) {
+    case FontType::FREETYPE:
+    case FontType::FONTCONFIG:
+    case FontType::MAC:
+    case FontType::GDI:
+    case FontType::DWRITE:
+      return true;
+    default:
+      return false;
+  }
+}
+
+void DrawTargetSkia::DrawGlyphs(ScaledFont* aFont, const GlyphBuffer& aBuffer,
+                                const Pattern& aPattern,
+                                const StrokeOptions* aStrokeOptions,
+                                const DrawOptions& aOptions) {
+  if (!CanDrawFont(aFont)) {
+    return;
+  }
+
+  MarkChanged();
+
+  ScaledFontBase* skiaFont = static_cast<ScaledFontBase*>(aFont);
+  SkTypeface* typeface = skiaFont->GetSkTypeface();
+  if (!typeface) {
+    return;
+  }
+
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern);
+  if (aStrokeOptions && !StrokeOptionsToPaint(paint.mPaint, *aStrokeOptions)) {
+    return;
+  }
+
+  AntialiasMode aaMode = aFont->GetDefaultAAMode();
+  if (aOptions.mAntialiasMode != AntialiasMode::DEFAULT) {
+    aaMode = aOptions.mAntialiasMode;
+  }
+  bool aaEnabled = aaMode != AntialiasMode::NONE;
+  paint.mPaint.setAntiAlias(aaEnabled);
+
+  SkFont font(sk_ref_sp(typeface), SkFloatToScalar(skiaFont->mSize));
+
+  bool useSubpixelAA =
+      GetPermitSubpixelAA() &&
+      (aaMode == AntialiasMode::DEFAULT || aaMode == AntialiasMode::SUBPIXEL);
+  font.setEdging(useSubpixelAA ? SkFont::Edging::kSubpixelAntiAlias
+                               : (aaEnabled ? SkFont::Edging::kAntiAlias
+                                            : SkFont::Edging::kAlias));
+
+  skiaFont->SetupSkFontDrawOptions(font);
+
+  // Limit the amount of internal batch allocations Skia does.
+  const uint32_t kMaxGlyphBatchSize = 8192;
+
+  for (uint32_t offset = 0; offset < aBuffer.mNumGlyphs;) {
+    uint32_t batchSize =
+        std::min(aBuffer.mNumGlyphs - offset, kMaxGlyphBatchSize);
+    SkTextBlobBuilder builder;
+    auto runBuffer = builder.allocRunPos(font, batchSize);
+    for (uint32_t i = 0; i < batchSize; i++, offset++) {
+      runBuffer.glyphs[i] = aBuffer.mGlyphs[offset].mIndex;
+      runBuffer.points()[i] = PointToSkPoint(aBuffer.mGlyphs[offset].mPosition);
+    }
+
+    sk_sp<SkTextBlob> text = builder.make();
+    mCanvas->drawTextBlob(text, 0, 0, paint.mPaint);
+  }
+}
+
+Maybe<Rect> DrawTargetSkia::GetGlyphLocalBounds(
+    ScaledFont* aFont, const GlyphBuffer& aBuffer, const Pattern& aPattern,
+    const StrokeOptions* aStrokeOptions, const DrawOptions& aOptions) {
+  if (!CanDrawFont(aFont)) {
+    return Nothing();
+  }
+
+  ScaledFontBase* skiaFont = static_cast<ScaledFontBase*>(aFont);
+  SkTypeface* typeface = skiaFont->GetSkTypeface();
+  if (!typeface) {
+    return Nothing();
+  }
+
+  AutoPaintSetup paint(mCanvas, aOptions, aPattern);
+  if (aStrokeOptions && !StrokeOptionsToPaint(paint.mPaint, *aStrokeOptions)) {
+    return Nothing();
+  }
+
+  AntialiasMode aaMode = aFont->GetDefaultAAMode();
+  if (aOptions.mAntialiasMode != AntialiasMode::DEFAULT) {
+    aaMode = aOptions.mAntialiasMode;
+  }
+  bool aaEnabled = aaMode != AntialiasMode::NONE;
+  paint.mPaint.setAntiAlias(aaEnabled);
+
+  SkFont font(sk_ref_sp(typeface), SkFloatToScalar(skiaFont->mSize));
+
+  bool useSubpixelAA =
+      GetPermitSubpixelAA() &&
+      (aaMode == AntialiasMode::DEFAULT || aaMode == AntialiasMode::SUBPIXEL);
+  font.setEdging(useSubpixelAA ? SkFont::Edging::kSubpixelAntiAlias
+                               : (aaEnabled ? SkFont::Edging::kAntiAlias
+                                            : SkFont::Edging::kAlias));
+
+  skiaFont->SetupSkFontDrawOptions(font);
+
+  // Limit the amount of internal batch allocations Skia does.
+  const uint32_t kMaxGlyphBatchSize = 8192;
+
+  // Avoid using TextBlobBuilder for bounds computations as the conservative
+  // bounds can be wrong due to buggy font metrics. Instead, explicitly compute
+  // tight bounds directly with the SkFont.
+  Vector<SkGlyphID, 32> glyphs;
+  Vector<SkRect, 32> rects;
+  Rect bounds;
+  for (uint32_t offset = 0; offset < aBuffer.mNumGlyphs;) {
+    uint32_t batchSize =
+        std::min(aBuffer.mNumGlyphs - offset, kMaxGlyphBatchSize);
+    if (glyphs.resizeUninitialized(batchSize) &&
+        rects.resizeUninitialized(batchSize)) {
+      for (uint32_t i = 0; i < batchSize; i++) {
+        glyphs[i] = aBuffer.mGlyphs[offset + i].mIndex;
+      }
+      font.getBounds(glyphs.begin(), batchSize, rects.begin(), nullptr);
+      for (uint32_t i = 0; i < batchSize; i++) {
+        bounds = bounds.Union(SkRectToRect(rects[i]) +
+                              aBuffer.mGlyphs[offset + i].mPosition);
+      }
+    }
+    offset += batchSize;
+  }
+
+  SkRect storage;
+  bounds = SkRectToRect(
+      paint.mPaint.computeFastBounds(RectToSkRect(bounds), &storage));
+
+  if (bounds.IsEmpty()) {
+    return Nothing();
+  }
+
+  return Some(bounds);
+}
+
+void DrawTargetSkia::FillGlyphs(ScaledFont* aFont, const GlyphBuffer& aBuffer,
+                                const Pattern& aPattern,
+                                const DrawOptions& aOptions) {
+  DrawGlyphs(aFont, aBuffer, aPattern, nullptr, aOptions);
+}
+
+void DrawTargetSkia::StrokeGlyphs(ScaledFont* aFont, const GlyphBuffer& aBuffer,
+                                  const Pattern& aPattern,
+                                  const StrokeOptions& aStrokeOptions,
+                                  const DrawOptions& aOptions) {
+  DrawGlyphs(aFont, aBuffer, aPattern, &aStrokeOptions, aOptions);
+}
+
+void DrawTargetSkia::Mask(const Pattern& aSource, const Pattern& aMask,
+                          const DrawOptions& aOptions) {
+  SkIRect maskBounds;
+  if (!mCanvas->getDeviceClipBounds(&maskBounds)) {
+    return;
+  }
+  SkPoint maskOrigin;
+  maskOrigin.iset(maskBounds.fLeft, maskBounds.fTop);
+
+  SkMatrix maskMatrix = mCanvas->getTotalMatrix();
+  maskMatrix.postTranslate(-maskOrigin.fX, -maskOrigin.fY);
+
+  MarkChanged();
+  AutoPaintSetup paint(mCanvas, aOptions, aSource, nullptr, &maskMatrix);
+
+  Maybe<MutexAutoLock> lock;
+  SkPaint maskPaint;
+  SetPaintPattern(maskPaint, aMask, lock);
+
+  SkBitmap maskBitmap;
+  if (!maskBitmap.tryAllocPixelsFlags(
+          SkImageInfo::MakeA8(maskBounds.width(), maskBounds.height()),
+          SkBitmap::kZeroPixels_AllocFlag)) {
+    return;
+  }
+
+  SkCanvas maskCanvas(maskBitmap);
+  maskCanvas.setMatrix(maskMatrix);
+  maskCanvas.drawPaint(maskPaint);
+
+  mCanvas->save();
+  mCanvas->resetMatrix();
+
+  mCanvas->drawBitmap(maskBitmap, maskOrigin.fX, maskOrigin.fY, &paint.mPaint);
+
+  mCanvas->restore();
+}
+
+void DrawTargetSkia::MaskSurface(const Pattern& aSource, SourceSurface* aMask,
+                                 Point aOffset, const DrawOptions& aOptions) {
+  MarkChanged();
+
+  SkMatrix invOffset = SkMatrix::MakeTrans(SkFloatToScalar(-aOffset.x),
+                                           SkFloatToScalar(-aOffset.y));
+  AutoPaintSetup paint(mCanvas, aOptions, aSource, nullptr, &invOffset);
+
+  Maybe<MutexAutoLock> lock;
+  sk_sp<SkImage> alphaMask = ExtractAlphaForSurface(aMask, lock);
+  if (!alphaMask) {
+    gfxDebug() << *this << ": MaskSurface() failed to extract alpha for mask";
+    return;
+  }
+
+  mCanvas->drawImage(alphaMask, aOffset.x + aMask->GetRect().x,
+                     aOffset.y + aMask->GetRect().y, &paint.mPaint);
+}
+
+bool DrawTarget::Draw3DTransformedSurface(SourceSurface* aSurface,
+                                          const Matrix4x4& aMatrix) {
+  // Composite the 3D transform with the DT's transform.
+  Matrix4x4 fullMat = aMatrix * Matrix4x4::From2D(mTransform);
+  if (fullMat.IsSingular()) {
+    return false;
+  }
+  // Transform the surface bounds and clip to this DT.
+  IntRect xformBounds = RoundedOut(fullMat.TransformAndClipBounds(
+      Rect(Point(0, 0), Size(aSurface->GetSize())),
+      Rect(Point(0, 0), Size(GetSize()))));
+  if (xformBounds.IsEmpty()) {
+    return true;
+  }
+  // Offset the matrix by the transformed origin.
+  fullMat.PostTranslate(-xformBounds.X(), -xformBounds.Y(), 0);
+
+  // Read in the source data.
+  Maybe<MutexAutoLock> lock;
+  sk_sp<SkImage> srcImage = GetSkImageForSurface(aSurface, &lock);
+  if (!srcImage) {
+    return true;
+  }
+
+  // Set up an intermediate destination surface only the size of the transformed
+  // bounds. Try to pass through the source's format unmodified in both the BGRA
+  // and ARGB cases.
+  RefPtr<DataSourceSurface> dstSurf = Factory::CreateDataSourceSurface(
+      xformBounds.Size(),
+      !srcImage->isOpaque() ? aSurface->GetFormat()
+                            : SurfaceFormat::A8R8G8B8_UINT32,
+      true);
+  if (!dstSurf) {
+    return false;
+  }
+
+  DataSourceSurface::ScopedMap map(dstSurf, DataSourceSurface::READ_WRITE);
+  std::unique_ptr<SkCanvas> dstCanvas(SkCanvas::MakeRasterDirect(
+      SkImageInfo::Make(xformBounds.Width(), xformBounds.Height(),
+                        GfxFormatToSkiaColorType(dstSurf->GetFormat()),
+                        kPremul_SkAlphaType),
+      map.GetData(), map.GetStride()));
+  if (!dstCanvas) {
+    return false;
+  }
+
+  // Do the transform.
+  SkPaint paint;
+  paint.setAntiAlias(true);
+  paint.setFilterQuality(kLow_SkFilterQuality);
+  paint.setBlendMode(SkBlendMode::kSrc);
+
+  SkMatrix xform;
+  GfxMatrixToSkiaMatrix(fullMat, xform);
+  dstCanvas->setMatrix(xform);
+
+  dstCanvas->drawImage(srcImage, 0, 0, &paint);
+  dstCanvas->flush();
+
+  // Temporarily reset the DT's transform, since it has already been composed
+  // above.
+  Matrix origTransform = mTransform;
+  SetTransform(Matrix());
+
+  // Draw the transformed surface within the transformed bounds.
+  DrawSurface(dstSurf, Rect(xformBounds),
+              Rect(Point(0, 0), Size(xformBounds.Size())));
+
+  SetTransform(origTransform);
+
+  return true;
+}
+
+bool DrawTargetSkia::Draw3DTransformedSurface(SourceSurface* aSurface,
+                                              const Matrix4x4& aMatrix) {
+  if (aMatrix.IsSingular()) {
+    return false;
+  }
+
+  MarkChanged();
+
+  Maybe<MutexAutoLock> lock;
+  sk_sp<SkImage> image = GetSkImageForSurface(aSurface, &lock);
+  if (!image) {
+    return true;
+  }
+
+  mCanvas->save();
+
+  SkPaint paint;
+  paint.setAntiAlias(true);
+  paint.setFilterQuality(kLow_SkFilterQuality);
+
+  SkMatrix xform;
+  GfxMatrixToSkiaMatrix(aMatrix, xform);
+  mCanvas->concat(xform);
+
+  mCanvas->drawImage(image, 0, 0, &paint);
+
+  mCanvas->restore();
+
+  return true;
+}
+
+already_AddRefed<SourceSurface> DrawTargetSkia::CreateSourceSurfaceFromData(
+    unsigned char* aData, const IntSize& aSize, int32_t aStride,
+    SurfaceFormat aFormat) const {
+  RefPtr<SourceSurfaceSkia> newSurf = new SourceSurfaceSkia();
+
+  if (!newSurf->InitFromData(aData, aSize, aStride, aFormat)) {
+    gfxDebug() << *this
+               << ": Failure to create source surface from data. Size: "
+               << aSize;
+    return nullptr;
+  }
+
+  return newSurf.forget();
+}
+
+already_AddRefed<DrawTarget> DrawTargetSkia::CreateSimilarDrawTarget(
+    const IntSize& aSize, SurfaceFormat aFormat) const {
+  RefPtr<DrawTargetSkia> target = new DrawTargetSkia();
+#ifdef DEBUG
+  if (!IsBackedByPixels(mCanvas)) {
+    // If our canvas is backed by vector storage such as PDF then we want to
+    // create a new DrawTarget with similar storage to avoid losing fidelity
+    // (fidelity will be lost if the returned DT is Snapshot()'ed and drawn
+    // back onto us since a raster will be drawn instead of vector commands).
+    NS_WARNING("Not backed by pixels - we need to handle PDF backed SkCanvas");
+  }
+#endif
+
+  if (!target->Init(aSize, aFormat)) {
+    return nullptr;
+  }
+  return target.forget();
+}
+
+bool DrawTargetSkia::CanCreateSimilarDrawTarget(const IntSize& aSize,
+                                                SurfaceFormat aFormat) const {
+  auto minmaxPair = std::minmax(aSize.width, aSize.height);
+  return minmaxPair.first > 0 &&
+         size_t(minmaxPair.second) < GetMaxSurfaceSize();
+}
+
+RefPtr<DrawTarget> DrawTargetSkia::CreateClippedDrawTarget(
+    const Rect& aBounds, SurfaceFormat aFormat) {
+  SkIRect clipBounds;
+
+  RefPtr<DrawTarget> result;
+  // Doing this save()/restore() dance is wasteful
+  mCanvas->save();
+  if (!aBounds.IsEmpty()) {
+    mCanvas->clipRect(RectToSkRect(aBounds), SkClipOp::kIntersect, true);
+  }
+  if (mCanvas->getDeviceClipBounds(&clipBounds)) {
+    RefPtr<DrawTarget> dt = CreateSimilarDrawTarget(
+        IntSize(clipBounds.width(), clipBounds.height()), aFormat);
+    if (dt) {
+      result = gfx::Factory::CreateOffsetDrawTarget(
+          dt, IntPoint(clipBounds.x(), clipBounds.y()));
+      if (result) {
+        result->SetTransform(mTransform);
+      }
+    }
+  } else {
+    // Everything is clipped but we still want some kind of surface
+    result = CreateSimilarDrawTarget(IntSize(1, 1), aFormat);
+  }
+  mCanvas->restore();
+  return result;
+}
+
+already_AddRefed<SourceSurface>
+DrawTargetSkia::OptimizeSourceSurfaceForUnknownAlpha(
+    SourceSurface* aSurface) const {
+  if (aSurface->GetType() == SurfaceType::SKIA) {
+    RefPtr<SourceSurface> surface(aSurface);
+    return surface.forget();
+  }
+
+  RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
+  DataSourceSurface::ScopedMap map(dataSurface, DataSourceSurface::READ_WRITE);
+
+  // For plugins, GDI can sometimes just write 0 to the alpha channel
+  // even for RGBX formats. In this case, we have to manually write
+  // the alpha channel to make Skia happy with RGBX and in case GDI
+  // writes some bad data. Luckily, this only happens on plugins.
+  WriteRGBXFormat(map.GetData(), dataSurface->GetSize(), map.GetStride(),
+                  dataSurface->GetFormat());
+  return dataSurface.forget();
+}
+
+already_AddRefed<SourceSurface> DrawTargetSkia::OptimizeSourceSurface(
+    SourceSurface* aSurface) const {
+  if (aSurface->GetType() == SurfaceType::SKIA) {
+    RefPtr<SourceSurface> surface(aSurface);
+    return surface.forget();
+  }
+
+  // If we're not using skia-gl then drawing doesn't require any
+  // uploading, so any data surface is fine. Call GetDataSurface
+  // to trigger any required readback so that it only happens
+  // once.
+  RefPtr<DataSourceSurface> dataSurface = aSurface->GetDataSurface();
+#ifdef DEBUG
+  DataSourceSurface::ScopedMap map(dataSurface, DataSourceSurface::READ);
+  MOZ_ASSERT(VerifyRGBXFormat(map.GetData(), dataSurface->GetSize(),
+                              map.GetStride(), dataSurface->GetFormat()));
+#endif
+  return dataSurface.forget();
+}
+
+already_AddRefed<SourceSurface>
+DrawTargetSkia::CreateSourceSurfaceFromNativeSurface(
+    const NativeSurface& aSurface) const {
+  return nullptr;
+}
+
+void DrawTargetSkia::BlendSurface(SourceSurface* aSurface,
+                                  const IntRect& aSourceRect,
+                                  const IntPoint& aDestination,
+                                  CompositionOp aOperator) {
+  MarkChanged();
+
+  Maybe<MutexAutoLock> lock;
+  sk_sp<SkImage> image = GetSkImageForSurface(aSurface, &lock);
+  if (!image) {
+    return;
+  }
+
+  mCanvas->save();
+  mCanvas->setMatrix(SkMatrix::MakeTrans(SkIntToScalar(aDestination.x),
+                                         SkIntToScalar(aDestination.y)));
+  mCanvas->clipRect(SkRect::MakeIWH(aSourceRect.Width(), aSourceRect.Height()),
+                    SkClipOp::kReplace_deprecated);
+
+  SkPaint paint;
+  if (aOperator == CompositionOp::OP_SOURCE) {
+    if (!image->isOpaque()) {
+      // Keep the xfermode as SOURCE_OVER for opaque bitmaps
+      // http://code.google.com/p/skia/issues/detail?id=628
+      paint.setBlendMode(SkBlendMode::kSrc);
+    }
+    // drawImage with A8 images ends up doing a mask operation
+    // so we need to clear before
+    if (image->isAlphaOnly()) {
+      mCanvas->clear(SK_ColorTRANSPARENT);
+    }
+  } else {
+    paint.setBlendMode(GfxOpToSkiaOp(aOperator));
+  }
+
+  mCanvas->drawImage(image, -SkIntToScalar(aSourceRect.X()),
+                     -SkIntToScalar(aSourceRect.Y()), &paint);
+  mCanvas->restore();
+}
+
+static inline SkPixelGeometry GetSkPixelGeometry() {
+  return Factory::GetBGRSubpixelOrder() ? kBGR_H_SkPixelGeometry
+                                        : kRGB_H_SkPixelGeometry;
+}
+
+template <typename T>
+[[nodiscard]] static already_AddRefed<T> AsRefPtr(sk_sp<T>&& aSkPtr) {
+  return already_AddRefed<T>(aSkPtr.release());
+}
+
+bool DrawTargetSkia::Init(const IntSize& aSize, SurfaceFormat aFormat) {
+  if (size_t(std::max(aSize.width, aSize.height)) > GetMaxSurfaceSize()) {
+    return false;
+  }
+
+  // we need to have surfaces that have a stride aligned to 4 for interop with
+  // cairo
+  SkImageInfo info = MakeSkiaImageInfo(aSize, aFormat);
+  size_t stride = SkAlign4(info.minRowBytes());
+  SkSurfaceProps props(0, GetSkPixelGeometry());
+
+  if (aFormat == SurfaceFormat::A8) {
+    // Skia does not fully allocate the last row according to stride.
+    // Since some of our algorithms (i.e. blur) depend on this, we must allocate
+    // the bitmap pixels manually.
+    CheckedInt<size_t> size = stride;
+    size *= info.height();
+    // We need to leave room for an additional 3 bytes for a potential overrun
+    // in our blurring code.
+    size += 3;
+    if (!size.isValid()) {
+      return false;
+    }
+    void* buf = sk_malloc_flags(size.value(), SK_MALLOC_ZERO_INITIALIZE);
+    if (!buf) {
+      return false;
+    }
+    mSurface = AsRefPtr(SkSurface::MakeRasterDirectReleaseProc(
+        info, buf, stride, FreeAlphaPixels, nullptr, &props));
+  } else {
+    mSurface = AsRefPtr(SkSurface::MakeRaster(info, stride, &props));
+  }
+  if (!mSurface) {
+    return false;
+  }
+
+  mSize = aSize;
+  mFormat = aFormat;
+  mCanvas = mSurface->getCanvas();
+  SetPermitSubpixelAA(IsOpaque(mFormat));
+
+  if (info.isOpaque()) {
+    mCanvas->clear(SK_ColorBLACK);
+  }
+  return true;
+}
+
+bool DrawTargetSkia::Init(SkCanvas* aCanvas) {
+  mCanvas = aCanvas;
+
+  SkImageInfo imageInfo = mCanvas->imageInfo();
+
+  // If the canvas is backed by pixels we clear it to be on the safe side.  If
+  // it's not (for example, for PDF output) we don't.
+  if (IsBackedByPixels(mCanvas)) {
+    SkColor clearColor =
+        imageInfo.isOpaque() ? SK_ColorBLACK : SK_ColorTRANSPARENT;
+    mCanvas->clear(clearColor);
+  }
+
+  SkISize size = mCanvas->getBaseLayerSize();
+  mSize.width = size.width();
+  mSize.height = size.height();
+  mFormat =
+      SkiaColorTypeToGfxFormat(imageInfo.colorType(), imageInfo.alphaType());
+  SetPermitSubpixelAA(IsOpaque(mFormat));
+  return true;
+}
+
+bool DrawTargetSkia::Init(unsigned char* aData, const IntSize& aSize,
+                          int32_t aStride, SurfaceFormat aFormat,
+                          bool aUninitialized) {
+  MOZ_ASSERT((aFormat != SurfaceFormat::B8G8R8X8) || aUninitialized ||
+             VerifyRGBXFormat(aData, aSize, aStride, aFormat));
+
+  SkSurfaceProps props(0, GetSkPixelGeometry());
+  mSurface = AsRefPtr(SkSurface::MakeRasterDirect(
+      MakeSkiaImageInfo(aSize, aFormat), aData, aStride, &props));
+  if (!mSurface) {
+    return false;
+  }
+
+  mSize = aSize;
+  mFormat = aFormat;
+  mCanvas = mSurface->getCanvas();
+  SetPermitSubpixelAA(IsOpaque(mFormat));
+  return true;
+}
+
+bool DrawTargetSkia::Init(RefPtr<DataSourceSurface>&& aSurface) {
+  auto map =
+      new DataSourceSurface::ScopedMap(aSurface, DataSourceSurface::READ_WRITE);
+  if (!map->IsMapped()) {
+    delete map;
+    return false;
+  }
+
+  SurfaceFormat format = aSurface->GetFormat();
+  IntSize size = aSurface->GetSize();
+  MOZ_ASSERT((format != SurfaceFormat::B8G8R8X8) ||
+             VerifyRGBXFormat(map->GetData(), size, map->GetStride(), format));
+
+  SkSurfaceProps props(0, GetSkPixelGeometry());
+  mSurface = AsRefPtr(SkSurface::MakeRasterDirectReleaseProc(
+      MakeSkiaImageInfo(size, format), map->GetData(), map->GetStride(),
+      DrawTargetSkia::ReleaseMappedSkSurface, map, &props));
+  if (!mSurface) {
+    delete map;
+    return false;
+  }
+
+  // map is now owned by mSurface
+  mBackingSurface = std::move(aSurface);
+  mSize = size;
+  mFormat = format;
+  mCanvas = mSurface->getCanvas();
+  SetPermitSubpixelAA(IsOpaque(format));
+  return true;
+}
+
+/* static */ void DrawTargetSkia::ReleaseMappedSkSurface(void* aPixels,
+                                                         void* aContext) {
+  auto map = reinterpret_cast<DataSourceSurface::ScopedMap*>(aContext);
+  delete map;
+}
+
+void DrawTargetSkia::SetTransform(const Matrix& aTransform) {
+  SkMatrix mat;
+  GfxMatrixToSkiaMatrix(aTransform, mat);
+  mCanvas->setMatrix(mat);
+  mTransform = aTransform;
+}
+
+void* DrawTargetSkia::GetNativeSurface(NativeSurfaceType aType) {
+  return nullptr;
+}
+
+already_AddRefed<PathBuilder> DrawTargetSkia::CreatePathBuilder(
+    FillRule aFillRule) const {
+  return MakeAndAddRef<PathBuilderSkia>(aFillRule);
+}
+
+void DrawTargetSkia::Clear(const Rect& aRect, bool aClipped) {
+  MarkChanged();
+  mCanvas->save();
+  if (aClipped) {
+    // Restrict clearing to the clip region if requested.
+    mCanvas->clipRect(RectToSkRect(aRect), SkClipOp::kIntersect, true);
+  } else {
+    // Otherwise, clear the entire rect.
+    mCanvas->resetMatrix();
+    mCanvas->clipRect(RectToSkRect(aRect), SkClipOp::kReplace_deprecated);
+  }
+  SkColor clearColor = (mFormat == SurfaceFormat::B8G8R8X8)
+                           ? SK_ColorBLACK
+                           : SK_ColorTRANSPARENT;
+  mCanvas->clear(clearColor);
+  mCanvas->restore();
+}
+
+void DrawTargetSkia::PushClip(const Path* aPath) {
+  if (aPath->GetBackendType() != BackendType::SKIA) {
+    return;
+  }
+
+  const PathSkia* skiaPath = static_cast<const PathSkia*>(aPath);
+  mCanvas->save();
+  mCanvas->clipPath(skiaPath->GetPath(), SkClipOp::kIntersect, true);
+}
+
+void DrawTargetSkia::PushDeviceSpaceClipRects(const IntRect* aRects,
+                                              uint32_t aCount) {
+  // Build a region by unioning all the rects together.
+  SkRegion region;
+  for (uint32_t i = 0; i < aCount; i++) {
+    region.op(IntRectToSkIRect(aRects[i]), SkRegion::kUnion_Op);
+  }
+
+  // Clip with the resulting region. clipRegion does not transform
+  // this region by the current transform, unlike the other SkCanvas
+  // clip methods, so it is just passed through in device-space.
+  mCanvas->save();
+  mCanvas->clipRegion(region, SkClipOp::kIntersect);
+}
+
+void DrawTargetSkia::PushClipRect(const Rect& aRect) {
+  SkRect rect = RectToSkRect(aRect);
+
+  mCanvas->save();
+  mCanvas->clipRect(rect, SkClipOp::kIntersect, true);
+}
+
+void DrawTargetSkia::PopClip() {
+  mCanvas->restore();
+  SetTransform(GetTransform());
+}
+
+bool DrawTargetSkia::RemoveAllClips() {
+  mCanvas->restoreToCount(1);
+  SetTransform(GetTransform());
+  return true;
+}
+
+// Get clip bounds in device space for the clipping region. By default, only
+// bounds for simple (empty or rect) regions are reported. If explicitly
+// allowed, the bounds will be reported for complex (all other) regions as well.
+Maybe<IntRect> DrawTargetSkia::GetDeviceClipRect(bool aAllowComplex) const {
+  if (mCanvas->isClipEmpty()) {
+    return Some(IntRect());
+  }
+  if (aAllowComplex || mCanvas->isClipRect()) {
+    SkIRect deviceBounds;
+    if (mCanvas->getDeviceClipBounds(&deviceBounds)) {
+      return Some(SkIRectToIntRect(deviceBounds));
+    }
+  }
+  return Nothing();
+}
+
+void DrawTargetSkia::PushLayer(bool aOpaque, Float aOpacity,
+                               SourceSurface* aMask,
+                               const Matrix& aMaskTransform,
+                               const IntRect& aBounds, bool aCopyBackground) {
+  PushLayerWithBlend(aOpaque, aOpacity, aMask, aMaskTransform, aBounds,
+                     aCopyBackground, CompositionOp::OP_OVER);
+}
+
+void DrawTargetSkia::PushLayerWithBlend(bool aOpaque, Float aOpacity,
+                                        SourceSurface* aMask,
+                                        const Matrix& aMaskTransform,
+                                        const IntRect& aBounds,
+                                        bool aCopyBackground,
+                                        CompositionOp aCompositionOp) {
+  PushedLayer layer(GetPermitSubpixelAA(), aMask);
+  mPushedLayers.push_back(layer);
+
+  SkPaint paint;
+
+  paint.setAlpha(ColorFloatToByte(aOpacity));
+  paint.setBlendMode(GfxOpToSkiaOp(aCompositionOp));
+
+  // aBounds is supplied in device space, but SaveLayerRec wants local space.
+  SkRect bounds = IntRectToSkRect(aBounds);
+  if (!bounds.isEmpty()) {
+    SkMatrix inverseCTM;
+    if (mCanvas->getTotalMatrix().invert(&inverseCTM)) {
+      inverseCTM.mapRect(&bounds);
+    } else {
+      bounds.setEmpty();
+    }
+  }
+
+  // We don't pass a lock object to GetSkImageForSurface here, to force a
+  // copy of the data if this is a copy-on-write snapshot. If we instead held
+  // the lock until the corresponding PopLayer, we'd risk deadlocking if someone
+  // tried to touch the originating DrawTarget while the layer was pushed.
+  sk_sp<SkImage> clipImage =
+      aMask ? GetSkImageForSurface(aMask, nullptr) : nullptr;
+  SkMatrix clipMatrix;
+  GfxMatrixToSkiaMatrix(aMaskTransform, clipMatrix);
+  if (aMask) {
+    clipMatrix.preTranslate(aMask->GetRect().X(), aMask->GetRect().Y());
+  }
+
+  SkCanvas::SaveLayerRec saveRec(
+      aBounds.IsEmpty() ? nullptr : &bounds, &paint, nullptr, clipImage.get(),
+      &clipMatrix,
+      SkCanvas::kPreserveLCDText_SaveLayerFlag |
+          (aCopyBackground ? SkCanvas::kInitWithPrevious_SaveLayerFlag : 0));
+
+  mCanvas->saveLayer(saveRec);
+
+  SetPermitSubpixelAA(aOpaque);
+
+#ifdef MOZ_WIDGET_COCOA
+  CGContextRelease(mCG);
+  mCG = nullptr;
+#endif
+}
+
+void DrawTargetSkia::PopLayer() {
+  MarkChanged();
+
+  MOZ_ASSERT(!mPushedLayers.empty());
+  const PushedLayer& layer = mPushedLayers.back();
+
+  mCanvas->restore();
+
+  SetTransform(GetTransform());
+  SetPermitSubpixelAA(layer.mOldPermitSubpixelAA);
+
+  mPushedLayers.pop_back();
+
+#ifdef MOZ_WIDGET_COCOA
+  CGContextRelease(mCG);
+  mCG = nullptr;
+#endif
+}
+
+already_AddRefed<GradientStops> DrawTargetSkia::CreateGradientStops(
+    GradientStop* aStops, uint32_t aNumStops, ExtendMode aExtendMode) const {
+  std::vector<GradientStop> stops;
+  stops.resize(aNumStops);
+  for (uint32_t i = 0; i < aNumStops; i++) {
+    stops[i] = aStops[i];
+  }
+  std::stable_sort(stops.begin(), stops.end());
+
+  return MakeAndAddRef<GradientStopsSkia>(stops, aNumStops, aExtendMode);
+}
+
+already_AddRefed<FilterNode> DrawTargetSkia::CreateFilter(FilterType aType) {
+  return FilterNodeSoftware::Create(aType);
+}
+
+void DrawTargetSkia::MarkChanged() {
+  // I'm not entirely certain whether this lock is needed, as multiple threads
+  // should never modify the DrawTarget at the same time anyway, but this seems
+  // like the safest.
+  MutexAutoLock lock(mSnapshotLock);
+  if (mSnapshot) {
+    if (mSnapshot->hasOneRef()) {
+      // No owners outside of this DrawTarget's own reference. Just dump it.
+      mSnapshot = nullptr;
+      return;
+    }
+
+    mSnapshot->DrawTargetWillChange();
+    mSnapshot = nullptr;
+
+    // Handle copying of any image snapshots bound to the surface.
+    if (mSurface) {
+      mSurface->notifyContentWillChange(SkSurface::kRetain_ContentChangeMode);
+    }
+  }
+}
+
+}  // namespace mozilla::gfx