Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

1 files changed, 3334 insertions, 0 deletions

diff --git a/image/imgLoader.cpp b/image/imgLoader.cpp
new file mode 100644
index 0000000000..dcfb031789
--- /dev/null
+++ b/image/imgLoader.cpp
@@ -0,0 +1,3334 @@
+/* -*- 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/. */
+
+// Undefine windows version of LoadImage because our code uses that name.
+#include "mozilla/ScopeExit.h"
+#include "nsIChildChannel.h"
+#undef LoadImage
+
+#include "imgLoader.h"
+
+#include <algorithm>
+#include <utility>
+
+#include "DecoderFactory.h"
+#include "Image.h"
+#include "ImageLogging.h"
+#include "ReferrerInfo.h"
+#include "imgRequestProxy.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/ChaosMode.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/LoadInfo.h"
+#include "mozilla/NullPrincipal.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/StaticPrefs_image.h"
+#include "mozilla/StaticPrefs_network.h"
+#include "mozilla/StoragePrincipalHelper.h"
+#include "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/nsMixedContentBlocker.h"
+#include "mozilla/image/ImageMemoryReporter.h"
+#include "mozilla/layers/CompositorManagerChild.h"
+#include "nsCOMPtr.h"
+#include "nsCRT.h"
+#include "nsComponentManagerUtils.h"
+#include "nsContentPolicyUtils.h"
+#include "nsContentSecurityManager.h"
+#include "nsContentUtils.h"
+#include "nsHttpChannel.h"
+#include "nsIAsyncVerifyRedirectCallback.h"
+#include "nsICacheInfoChannel.h"
+#include "nsIChannelEventSink.h"
+#include "nsIClassOfService.h"
+#include "nsIEffectiveTLDService.h"
+#include "nsIFile.h"
+#include "nsIFileURL.h"
+#include "nsIHttpChannel.h"
+#include "nsIInterfaceRequestor.h"
+#include "nsIInterfaceRequestorUtils.h"
+#include "nsIMemoryReporter.h"
+#include "nsINetworkPredictor.h"
+#include "nsIProgressEventSink.h"
+#include "nsIProtocolHandler.h"
+#include "nsImageModule.h"
+#include "nsMediaSniffer.h"
+#include "nsMimeTypes.h"
+#include "nsNetCID.h"
+#include "nsNetUtil.h"
+#include "nsProxyRelease.h"
+#include "nsQueryObject.h"
+#include "nsReadableUtils.h"
+#include "nsStreamUtils.h"
+#include "prtime.h"
+
+// we want to explore making the document own the load group
+// so we can associate the document URI with the load group.
+// until this point, we have an evil hack:
+#include "nsIHttpChannelInternal.h"
+#include "nsILoadGroupChild.h"
+#include "nsIDocShell.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::image;
+using namespace mozilla::net;
+
+MOZ_DEFINE_MALLOC_SIZE_OF(ImagesMallocSizeOf)
+
+class imgMemoryReporter final : public nsIMemoryReporter {
+  ~imgMemoryReporter() = default;
+
+ public:
+  NS_DECL_ISUPPORTS
+
+  NS_IMETHOD CollectReports(nsIHandleReportCallback* aHandleReport,
+                            nsISupports* aData, bool aAnonymize) override {
+    MOZ_ASSERT(NS_IsMainThread());
+
+    layers::CompositorManagerChild* manager =
+        mozilla::layers::CompositorManagerChild::GetInstance();
+    if (!manager || !StaticPrefs::image_mem_debug_reporting()) {
+      layers::SharedSurfacesMemoryReport sharedSurfaces;
+      FinishCollectReports(aHandleReport, aData, aAnonymize, sharedSurfaces);
+      return NS_OK;
+    }
+
+    RefPtr<imgMemoryReporter> self(this);
+    nsCOMPtr<nsIHandleReportCallback> handleReport(aHandleReport);
+    nsCOMPtr<nsISupports> data(aData);
+    manager->SendReportSharedSurfacesMemory(
+        [=](layers::SharedSurfacesMemoryReport aReport) {
+          self->FinishCollectReports(handleReport, data, aAnonymize, aReport);
+        },
+        [=](mozilla::ipc::ResponseRejectReason&& aReason) {
+          layers::SharedSurfacesMemoryReport sharedSurfaces;
+          self->FinishCollectReports(handleReport, data, aAnonymize,
+                                     sharedSurfaces);
+        });
+    return NS_OK;
+  }
+
+  void FinishCollectReports(
+      nsIHandleReportCallback* aHandleReport, nsISupports* aData,
+      bool aAnonymize, layers::SharedSurfacesMemoryReport& aSharedSurfaces) {
+    nsTArray<ImageMemoryCounter> chrome;
+    nsTArray<ImageMemoryCounter> content;
+    nsTArray<ImageMemoryCounter> uncached;
+
+    for (uint32_t i = 0; i < mKnownLoaders.Length(); i++) {
+      for (imgCacheEntry* entry : mKnownLoaders[i]->mCache.Values()) {
+        RefPtr<imgRequest> req = entry->GetRequest();
+        RecordCounterForRequest(req, &content, !entry->HasNoProxies());
+      }
+      MutexAutoLock lock(mKnownLoaders[i]->mUncachedImagesMutex);
+      for (RefPtr<imgRequest> req : mKnownLoaders[i]->mUncachedImages) {
+        RecordCounterForRequest(req, &uncached, req->HasConsumers());
+      }
+    }
+
+    // Note that we only need to anonymize content image URIs.
+
+    ReportCounterArray(aHandleReport, aData, chrome, "images/chrome",
+                       /* aAnonymize */ false, aSharedSurfaces);
+
+    ReportCounterArray(aHandleReport, aData, content, "images/content",
+                       aAnonymize, aSharedSurfaces);
+
+    // Uncached images may be content or chrome, so anonymize them.
+    ReportCounterArray(aHandleReport, aData, uncached, "images/uncached",
+                       aAnonymize, aSharedSurfaces);
+
+    // Report any shared surfaces that were not merged with the surface cache.
+    ImageMemoryReporter::ReportSharedSurfaces(aHandleReport, aData,
+                                              aSharedSurfaces);
+
+    nsCOMPtr<nsIMemoryReporterManager> imgr =
+        do_GetService("@mozilla.org/memory-reporter-manager;1");
+    if (imgr) {
+      imgr->EndReport();
+    }
+  }
+
+  static int64_t ImagesContentUsedUncompressedDistinguishedAmount() {
+    size_t n = 0;
+    for (uint32_t i = 0; i < imgLoader::sMemReporter->mKnownLoaders.Length();
+         i++) {
+      for (imgCacheEntry* entry :
+           imgLoader::sMemReporter->mKnownLoaders[i]->mCache.Values()) {
+        if (entry->HasNoProxies()) {
+          continue;
+        }
+
+        RefPtr<imgRequest> req = entry->GetRequest();
+        RefPtr<image::Image> image = req->GetImage();
+        if (!image) {
+          continue;
+        }
+
+        // Both this and EntryImageSizes measure
+        // images/content/raster/used/decoded memory.  This function's
+        // measurement is secondary -- the result doesn't go in the "explicit"
+        // tree -- so we use moz_malloc_size_of instead of ImagesMallocSizeOf to
+        // prevent DMD from seeing it reported twice.
+        SizeOfState state(moz_malloc_size_of);
+        ImageMemoryCounter counter(req, image, state, /* aIsUsed = */ true);
+
+        n += counter.Values().DecodedHeap();
+        n += counter.Values().DecodedNonHeap();
+        n += counter.Values().DecodedUnknown();
+      }
+    }
+    return n;
+  }
+
+  void RegisterLoader(imgLoader* aLoader) {
+    mKnownLoaders.AppendElement(aLoader);
+  }
+
+  void UnregisterLoader(imgLoader* aLoader) {
+    mKnownLoaders.RemoveElement(aLoader);
+  }
+
+ private:
+  nsTArray<imgLoader*> mKnownLoaders;
+
+  struct MemoryTotal {
+    MemoryTotal& operator+=(const ImageMemoryCounter& aImageCounter) {
+      if (aImageCounter.Type() == imgIContainer::TYPE_RASTER) {
+        if (aImageCounter.IsUsed()) {
+          mUsedRasterCounter += aImageCounter.Values();
+        } else {
+          mUnusedRasterCounter += aImageCounter.Values();
+        }
+      } else if (aImageCounter.Type() == imgIContainer::TYPE_VECTOR) {
+        if (aImageCounter.IsUsed()) {
+          mUsedVectorCounter += aImageCounter.Values();
+        } else {
+          mUnusedVectorCounter += aImageCounter.Values();
+        }
+      } else if (aImageCounter.Type() == imgIContainer::TYPE_REQUEST) {
+        // Nothing to do, we did not get to the point of having an image.
+      } else {
+        MOZ_CRASH("Unexpected image type");
+      }
+
+      return *this;
+    }
+
+    const MemoryCounter& UsedRaster() const { return mUsedRasterCounter; }
+    const MemoryCounter& UnusedRaster() const { return mUnusedRasterCounter; }
+    const MemoryCounter& UsedVector() const { return mUsedVectorCounter; }
+    const MemoryCounter& UnusedVector() const { return mUnusedVectorCounter; }
+
+   private:
+    MemoryCounter mUsedRasterCounter;
+    MemoryCounter mUnusedRasterCounter;
+    MemoryCounter mUsedVectorCounter;
+    MemoryCounter mUnusedVectorCounter;
+  };
+
+  // Reports all images of a single kind, e.g. all used chrome images.
+  void ReportCounterArray(nsIHandleReportCallback* aHandleReport,
+                          nsISupports* aData,
+                          nsTArray<ImageMemoryCounter>& aCounterArray,
+                          const char* aPathPrefix, bool aAnonymize,
+                          layers::SharedSurfacesMemoryReport& aSharedSurfaces) {
+    MemoryTotal summaryTotal;
+    MemoryTotal nonNotableTotal;
+
+    // Report notable images, and compute total and non-notable aggregate sizes.
+    for (uint32_t i = 0; i < aCounterArray.Length(); i++) {
+      ImageMemoryCounter& counter = aCounterArray[i];
+
+      if (aAnonymize) {
+        counter.URI().Truncate();
+        counter.URI().AppendPrintf("<anonymized-%u>", i);
+      } else {
+        // The URI could be an extremely long data: URI. Truncate if needed.
+        static const size_t max = 256;
+        if (counter.URI().Length() > max) {
+          counter.URI().Truncate(max);
+          counter.URI().AppendLiteral(" (truncated)");
+        }
+        counter.URI().ReplaceChar('/', '\\');
+      }
+
+      summaryTotal += counter;
+
+      if (counter.IsNotable() || StaticPrefs::image_mem_debug_reporting()) {
+        ReportImage(aHandleReport, aData, aPathPrefix, counter,
+                    aSharedSurfaces);
+      } else {
+        ImageMemoryReporter::TrimSharedSurfaces(counter, aSharedSurfaces);
+        nonNotableTotal += counter;
+      }
+    }
+
+    // Report non-notable images in aggregate.
+    ReportTotal(aHandleReport, aData, /* aExplicit = */ true, aPathPrefix,
+                "<non-notable images>/", nonNotableTotal);
+
+    // Report a summary in aggregate, outside of the explicit tree.
+    ReportTotal(aHandleReport, aData, /* aExplicit = */ false, aPathPrefix, "",
+                summaryTotal);
+  }
+
+  static void ReportImage(nsIHandleReportCallback* aHandleReport,
+                          nsISupports* aData, const char* aPathPrefix,
+                          const ImageMemoryCounter& aCounter,
+                          layers::SharedSurfacesMemoryReport& aSharedSurfaces) {
+    nsAutoCString pathPrefix("explicit/"_ns);
+    pathPrefix.Append(aPathPrefix);
+
+    switch (aCounter.Type()) {
+      case imgIContainer::TYPE_RASTER:
+        pathPrefix.AppendLiteral("/raster/");
+        break;
+      case imgIContainer::TYPE_VECTOR:
+        pathPrefix.AppendLiteral("/vector/");
+        break;
+      case imgIContainer::TYPE_REQUEST:
+        pathPrefix.AppendLiteral("/request/");
+        break;
+      default:
+        pathPrefix.AppendLiteral("/unknown=");
+        pathPrefix.AppendInt(aCounter.Type());
+        pathPrefix.AppendLiteral("/");
+        break;
+    }
+
+    pathPrefix.Append(aCounter.IsUsed() ? "used/" : "unused/");
+    if (aCounter.IsValidating()) {
+      pathPrefix.AppendLiteral("validating/");
+    }
+    if (aCounter.HasError()) {
+      pathPrefix.AppendLiteral("err/");
+    }
+
+    pathPrefix.AppendLiteral("progress=");
+    pathPrefix.AppendInt(aCounter.Progress(), 16);
+    pathPrefix.AppendLiteral("/");
+
+    pathPrefix.AppendLiteral("image(");
+    pathPrefix.AppendInt(aCounter.IntrinsicSize().width);
+    pathPrefix.AppendLiteral("x");
+    pathPrefix.AppendInt(aCounter.IntrinsicSize().height);
+    pathPrefix.AppendLiteral(", ");
+
+    if (aCounter.URI().IsEmpty()) {
+      pathPrefix.AppendLiteral("<unknown URI>");
+    } else {
+      pathPrefix.Append(aCounter.URI());
+    }
+
+    pathPrefix.AppendLiteral(")/");
+
+    ReportSurfaces(aHandleReport, aData, pathPrefix, aCounter, aSharedSurfaces);
+
+    ReportSourceValue(aHandleReport, aData, pathPrefix, aCounter.Values());
+  }
+
+  static void ReportSurfaces(
+      nsIHandleReportCallback* aHandleReport, nsISupports* aData,
+      const nsACString& aPathPrefix, const ImageMemoryCounter& aCounter,
+      layers::SharedSurfacesMemoryReport& aSharedSurfaces) {
+    for (const SurfaceMemoryCounter& counter : aCounter.Surfaces()) {
+      nsAutoCString surfacePathPrefix(aPathPrefix);
+      switch (counter.Type()) {
+        case SurfaceMemoryCounterType::NORMAL:
+          if (counter.IsLocked()) {
+            surfacePathPrefix.AppendLiteral("locked/");
+          } else {
+            surfacePathPrefix.AppendLiteral("unlocked/");
+          }
+          if (counter.IsFactor2()) {
+            surfacePathPrefix.AppendLiteral("factor2/");
+          }
+          if (counter.CannotSubstitute()) {
+            surfacePathPrefix.AppendLiteral("cannot_substitute/");
+          }
+          break;
+        case SurfaceMemoryCounterType::CONTAINER:
+          surfacePathPrefix.AppendLiteral("container/");
+          break;
+        default:
+          MOZ_ASSERT_UNREACHABLE("Unknown counter type");
+          break;
+      }
+
+      surfacePathPrefix.AppendLiteral("types=");
+      surfacePathPrefix.AppendInt(counter.Values().SurfaceTypes(), 16);
+      surfacePathPrefix.AppendLiteral("/surface(");
+      surfacePathPrefix.AppendInt(counter.Key().Size().width);
+      surfacePathPrefix.AppendLiteral("x");
+      surfacePathPrefix.AppendInt(counter.Key().Size().height);
+
+      if (!counter.IsFinished()) {
+        surfacePathPrefix.AppendLiteral(", incomplete");
+      }
+
+      if (counter.Values().ExternalHandles() > 0) {
+        surfacePathPrefix.AppendLiteral(", handles:");
+        surfacePathPrefix.AppendInt(
+            uint32_t(counter.Values().ExternalHandles()));
+      }
+
+      ImageMemoryReporter::AppendSharedSurfacePrefix(surfacePathPrefix, counter,
+                                                     aSharedSurfaces);
+
+      PlaybackType playback = counter.Key().Playback();
+      if (playback == PlaybackType::eAnimated) {
+        if (StaticPrefs::image_mem_debug_reporting()) {
+          surfacePathPrefix.AppendPrintf(
+              " (animation %4u)", uint32_t(counter.Values().FrameIndex()));
+        } else {
+          surfacePathPrefix.AppendLiteral(" (animation)");
+        }
+      }
+
+      if (counter.Key().Flags() != DefaultSurfaceFlags()) {
+        surfacePathPrefix.AppendLiteral(", flags:");
+        surfacePathPrefix.AppendInt(uint32_t(counter.Key().Flags()),
+                                    /* aRadix = */ 16);
+      }
+
+      if (counter.Key().Region()) {
+        const ImageIntRegion& region = counter.Key().Region().ref();
+        const gfx::IntRect& rect = region.Rect();
+        surfacePathPrefix.AppendLiteral(", region:[ rect=(");
+        surfacePathPrefix.AppendInt(rect.x);
+        surfacePathPrefix.AppendLiteral(",");
+        surfacePathPrefix.AppendInt(rect.y);
+        surfacePathPrefix.AppendLiteral(") ");
+        surfacePathPrefix.AppendInt(rect.width);
+        surfacePathPrefix.AppendLiteral("x");
+        surfacePathPrefix.AppendInt(rect.height);
+        if (region.IsRestricted()) {
+          const gfx::IntRect& restrict = region.Restriction();
+          if (restrict == rect) {
+            surfacePathPrefix.AppendLiteral(", restrict=rect");
+          } else {
+            surfacePathPrefix.AppendLiteral(", restrict=(");
+            surfacePathPrefix.AppendInt(restrict.x);
+            surfacePathPrefix.AppendLiteral(",");
+            surfacePathPrefix.AppendInt(restrict.y);
+            surfacePathPrefix.AppendLiteral(") ");
+            surfacePathPrefix.AppendInt(restrict.width);
+            surfacePathPrefix.AppendLiteral("x");
+            surfacePathPrefix.AppendInt(restrict.height);
+          }
+        }
+        if (region.GetExtendMode() != gfx::ExtendMode::CLAMP) {
+          surfacePathPrefix.AppendLiteral(", extendMode=");
+          surfacePathPrefix.AppendInt(int32_t(region.GetExtendMode()));
+        }
+        surfacePathPrefix.AppendLiteral("]");
+      }
+
+      const SVGImageContext& context = counter.Key().SVGContext();
+      surfacePathPrefix.AppendLiteral(", svgContext:[ ");
+      if (context.GetViewportSize()) {
+        const CSSIntSize& size = context.GetViewportSize().ref();
+        surfacePathPrefix.AppendLiteral("viewport=(");
+        surfacePathPrefix.AppendInt(size.width);
+        surfacePathPrefix.AppendLiteral("x");
+        surfacePathPrefix.AppendInt(size.height);
+        surfacePathPrefix.AppendLiteral(") ");
+      }
+      if (context.GetPreserveAspectRatio()) {
+        nsAutoString aspect;
+        context.GetPreserveAspectRatio()->ToString(aspect);
+        surfacePathPrefix.AppendLiteral("preserveAspectRatio=(");
+        LossyAppendUTF16toASCII(aspect, surfacePathPrefix);
+        surfacePathPrefix.AppendLiteral(") ");
+      }
+      if (auto scheme = context.GetColorScheme()) {
+        surfacePathPrefix.AppendLiteral("colorScheme=");
+        surfacePathPrefix.AppendInt(int32_t(*scheme));
+        surfacePathPrefix.AppendLiteral(" ");
+      }
+      if (context.GetContextPaint()) {
+        const SVGEmbeddingContextPaint* paint = context.GetContextPaint();
+        surfacePathPrefix.AppendLiteral("contextPaint=(");
+        if (paint->GetFill()) {
+          surfacePathPrefix.AppendLiteral(" fill=");
+          surfacePathPrefix.AppendInt(paint->GetFill()->ToABGR(), 16);
+        }
+        if (paint->GetFillOpacity() != 1.0) {
+          surfacePathPrefix.AppendLiteral(" fillOpa=");
+          surfacePathPrefix.AppendFloat(paint->GetFillOpacity());
+        }
+        if (paint->GetStroke()) {
+          surfacePathPrefix.AppendLiteral(" stroke=");
+          surfacePathPrefix.AppendInt(paint->GetStroke()->ToABGR(), 16);
+        }
+        if (paint->GetStrokeOpacity() != 1.0) {
+          surfacePathPrefix.AppendLiteral(" strokeOpa=");
+          surfacePathPrefix.AppendFloat(paint->GetStrokeOpacity());
+        }
+        surfacePathPrefix.AppendLiteral(" ) ");
+      }
+      surfacePathPrefix.AppendLiteral("]");
+
+      surfacePathPrefix.AppendLiteral(")/");
+
+      ReportValues(aHandleReport, aData, surfacePathPrefix, counter.Values());
+    }
+  }
+
+  static void ReportTotal(nsIHandleReportCallback* aHandleReport,
+                          nsISupports* aData, bool aExplicit,
+                          const char* aPathPrefix, const char* aPathInfix,
+                          const MemoryTotal& aTotal) {
+    nsAutoCString pathPrefix;
+    if (aExplicit) {
+      pathPrefix.AppendLiteral("explicit/");
+    }
+    pathPrefix.Append(aPathPrefix);
+
+    nsAutoCString rasterUsedPrefix(pathPrefix);
+    rasterUsedPrefix.AppendLiteral("/raster/used/");
+    rasterUsedPrefix.Append(aPathInfix);
+    ReportValues(aHandleReport, aData, rasterUsedPrefix, aTotal.UsedRaster());
+
+    nsAutoCString rasterUnusedPrefix(pathPrefix);
+    rasterUnusedPrefix.AppendLiteral("/raster/unused/");
+    rasterUnusedPrefix.Append(aPathInfix);
+    ReportValues(aHandleReport, aData, rasterUnusedPrefix,
+                 aTotal.UnusedRaster());
+
+    nsAutoCString vectorUsedPrefix(pathPrefix);
+    vectorUsedPrefix.AppendLiteral("/vector/used/");
+    vectorUsedPrefix.Append(aPathInfix);
+    ReportValues(aHandleReport, aData, vectorUsedPrefix, aTotal.UsedVector());
+
+    nsAutoCString vectorUnusedPrefix(pathPrefix);
+    vectorUnusedPrefix.AppendLiteral("/vector/unused/");
+    vectorUnusedPrefix.Append(aPathInfix);
+    ReportValues(aHandleReport, aData, vectorUnusedPrefix,
+                 aTotal.UnusedVector());
+  }
+
+  static void ReportValues(nsIHandleReportCallback* aHandleReport,
+                           nsISupports* aData, const nsACString& aPathPrefix,
+                           const MemoryCounter& aCounter) {
+    ReportSourceValue(aHandleReport, aData, aPathPrefix, aCounter);
+
+    ReportValue(aHandleReport, aData, KIND_HEAP, aPathPrefix, "decoded-heap",
+                "Decoded image data which is stored on the heap.",
+                aCounter.DecodedHeap());
+
+    ReportValue(aHandleReport, aData, KIND_NONHEAP, aPathPrefix,
+                "decoded-nonheap",
+                "Decoded image data which isn't stored on the heap.",
+                aCounter.DecodedNonHeap());
+
+    // We don't know for certain whether or not it is on the heap, so let's
+    // just report it as non-heap for reporting purposes.
+    ReportValue(aHandleReport, aData, KIND_NONHEAP, aPathPrefix,
+                "decoded-unknown",
+                "Decoded image data which is unknown to be on the heap or not.",
+                aCounter.DecodedUnknown());
+  }
+
+  static void ReportSourceValue(nsIHandleReportCallback* aHandleReport,
+                                nsISupports* aData,
+                                const nsACString& aPathPrefix,
+                                const MemoryCounter& aCounter) {
+    ReportValue(aHandleReport, aData, KIND_HEAP, aPathPrefix, "source",
+                "Raster image source data and vector image documents.",
+                aCounter.Source());
+  }
+
+  static void ReportValue(nsIHandleReportCallback* aHandleReport,
+                          nsISupports* aData, int32_t aKind,
+                          const nsACString& aPathPrefix,
+                          const char* aPathSuffix, const char* aDescription,
+                          size_t aValue) {
+    if (aValue == 0) {
+      return;
+    }
+
+    nsAutoCString desc(aDescription);
+    nsAutoCString path(aPathPrefix);
+    path.Append(aPathSuffix);
+
+    aHandleReport->Callback(""_ns, path, aKind, UNITS_BYTES, aValue, desc,
+                            aData);
+  }
+
+  static void RecordCounterForRequest(imgRequest* aRequest,
+                                      nsTArray<ImageMemoryCounter>* aArray,
+                                      bool aIsUsed) {
+    SizeOfState state(ImagesMallocSizeOf);
+    RefPtr<image::Image> image = aRequest->GetImage();
+    if (image) {
+      ImageMemoryCounter counter(aRequest, image, state, aIsUsed);
+      aArray->AppendElement(std::move(counter));
+    } else {
+      // We can at least record some information about the image from the
+      // request, and mark it as not knowing the image type yet.
+      ImageMemoryCounter counter(aRequest, state, aIsUsed);
+      aArray->AppendElement(std::move(counter));
+    }
+  }
+};
+
+NS_IMPL_ISUPPORTS(imgMemoryReporter, nsIMemoryReporter)
+
+NS_IMPL_ISUPPORTS(nsProgressNotificationProxy, nsIProgressEventSink,
+                  nsIChannelEventSink, nsIInterfaceRequestor)
+
+NS_IMETHODIMP
+nsProgressNotificationProxy::OnProgress(nsIRequest* request, int64_t progress,
+                                        int64_t progressMax) {
+  nsCOMPtr<nsILoadGroup> loadGroup;
+  request->GetLoadGroup(getter_AddRefs(loadGroup));
+
+  nsCOMPtr<nsIProgressEventSink> target;
+  NS_QueryNotificationCallbacks(mOriginalCallbacks, loadGroup,
+                                NS_GET_IID(nsIProgressEventSink),
+                                getter_AddRefs(target));
+  if (!target) {
+    return NS_OK;
+  }
+  return target->OnProgress(mImageRequest, progress, progressMax);
+}
+
+NS_IMETHODIMP
+nsProgressNotificationProxy::OnStatus(nsIRequest* request, nsresult status,
+                                      const char16_t* statusArg) {
+  nsCOMPtr<nsILoadGroup> loadGroup;
+  request->GetLoadGroup(getter_AddRefs(loadGroup));
+
+  nsCOMPtr<nsIProgressEventSink> target;
+  NS_QueryNotificationCallbacks(mOriginalCallbacks, loadGroup,
+                                NS_GET_IID(nsIProgressEventSink),
+                                getter_AddRefs(target));
+  if (!target) {
+    return NS_OK;
+  }
+  return target->OnStatus(mImageRequest, status, statusArg);
+}
+
+NS_IMETHODIMP
+nsProgressNotificationProxy::AsyncOnChannelRedirect(
+    nsIChannel* oldChannel, nsIChannel* newChannel, uint32_t flags,
+    nsIAsyncVerifyRedirectCallback* cb) {
+  // Tell the original original callbacks about it too
+  nsCOMPtr<nsILoadGroup> loadGroup;
+  newChannel->GetLoadGroup(getter_AddRefs(loadGroup));
+  nsCOMPtr<nsIChannelEventSink> target;
+  NS_QueryNotificationCallbacks(mOriginalCallbacks, loadGroup,
+                                NS_GET_IID(nsIChannelEventSink),
+                                getter_AddRefs(target));
+  if (!target) {
+    cb->OnRedirectVerifyCallback(NS_OK);
+    return NS_OK;
+  }
+
+  // Delegate to |target| if set, reusing |cb|
+  return target->AsyncOnChannelRedirect(oldChannel, newChannel, flags, cb);
+}
+
+NS_IMETHODIMP
+nsProgressNotificationProxy::GetInterface(const nsIID& iid, void** result) {
+  if (iid.Equals(NS_GET_IID(nsIProgressEventSink))) {
+    *result = static_cast<nsIProgressEventSink*>(this);
+    NS_ADDREF_THIS();
+    return NS_OK;
+  }
+  if (iid.Equals(NS_GET_IID(nsIChannelEventSink))) {
+    *result = static_cast<nsIChannelEventSink*>(this);
+    NS_ADDREF_THIS();
+    return NS_OK;
+  }
+  if (mOriginalCallbacks) {
+    return mOriginalCallbacks->GetInterface(iid, result);
+  }
+  return NS_NOINTERFACE;
+}
+
+static void NewRequestAndEntry(bool aForcePrincipalCheckForCacheEntry,
+                               imgLoader* aLoader, const ImageCacheKey& aKey,
+                               imgRequest** aRequest, imgCacheEntry** aEntry) {
+  RefPtr<imgRequest> request = new imgRequest(aLoader, aKey);
+  RefPtr<imgCacheEntry> entry =
+      new imgCacheEntry(aLoader, request, aForcePrincipalCheckForCacheEntry);
+  aLoader->AddToUncachedImages(request);
+  request.forget(aRequest);
+  entry.forget(aEntry);
+}
+
+static bool ShouldRevalidateEntry(imgCacheEntry* aEntry, nsLoadFlags aFlags,
+                                  bool aHasExpired) {
+  if (aFlags & nsIRequest::LOAD_BYPASS_CACHE) {
+    return false;
+  }
+  if (aFlags & nsIRequest::VALIDATE_ALWAYS) {
+    return true;
+  }
+  if (aEntry->GetMustValidate()) {
+    return true;
+  }
+  if (aHasExpired) {
+    // The cache entry has expired...  Determine whether the stale cache
+    // entry can be used without validation...
+    if (aFlags & (nsIRequest::LOAD_FROM_CACHE | nsIRequest::VALIDATE_NEVER |
+                  nsIRequest::VALIDATE_ONCE_PER_SESSION)) {
+      // LOAD_FROM_CACHE, VALIDATE_NEVER and VALIDATE_ONCE_PER_SESSION allow
+      // stale cache entries to be used unless they have been explicitly marked
+      // to indicate that revalidation is necessary.
+      return false;
+    }
+    // Entry is expired, revalidate.
+    return true;
+  }
+  return false;
+}
+
+/* Call content policies on cached images that went through a redirect */
+static bool ShouldLoadCachedImage(imgRequest* aImgRequest,
+                                  Document* aLoadingDocument,
+                                  nsIPrincipal* aTriggeringPrincipal,
+                                  nsContentPolicyType aPolicyType,
+                                  bool aSendCSPViolationReports) {
+  /* Call content policies on cached images - Bug 1082837
+   * Cached images are keyed off of the first uri in a redirect chain.
+   * Hence content policies don't get a chance to test the intermediate hops
+   * or the final destination.  Here we test the final destination using
+   * mFinalURI off of the imgRequest and passing it into content policies.
+   * For Mixed Content Blocker, we do an additional check to determine if any
+   * of the intermediary hops went through an insecure redirect with the
+   * mHadInsecureRedirect flag
+   */
+  bool insecureRedirect = aImgRequest->HadInsecureRedirect();
+  nsCOMPtr<nsIURI> contentLocation;
+  aImgRequest->GetFinalURI(getter_AddRefs(contentLocation));
+  nsresult rv;
+
+  nsCOMPtr<nsIPrincipal> loadingPrincipal =
+      aLoadingDocument ? aLoadingDocument->NodePrincipal()
+                       : aTriggeringPrincipal;
+  // If there is no context and also no triggeringPrincipal, then we use a fresh
+  // nullPrincipal as the loadingPrincipal because we can not create a loadinfo
+  // without a valid loadingPrincipal.
+  if (!loadingPrincipal) {
+    loadingPrincipal = NullPrincipal::CreateWithoutOriginAttributes();
+  }
+
+  nsCOMPtr<nsILoadInfo> secCheckLoadInfo = new LoadInfo(
+      loadingPrincipal, aTriggeringPrincipal, aLoadingDocument,
+      nsILoadInfo::SEC_ONLY_FOR_EXPLICIT_CONTENTSEC_CHECK, aPolicyType);
+
+  secCheckLoadInfo->SetSendCSPViolationEvents(aSendCSPViolationReports);
+
+  int16_t decision = nsIContentPolicy::REJECT_REQUEST;
+  rv = NS_CheckContentLoadPolicy(contentLocation, secCheckLoadInfo,
+                                 ""_ns,  // mime guess
+                                 &decision, nsContentUtils::GetContentPolicy());
+  if (NS_FAILED(rv) || !NS_CP_ACCEPTED(decision)) {
+    return false;
+  }
+
+  // We call all Content Policies above, but we also have to call mcb
+  // individually to check the intermediary redirect hops are secure.
+  if (insecureRedirect) {
+    // Bug 1314356: If the image ended up in the cache upgraded by HSTS and the
+    // page uses upgrade-inscure-requests it had an insecure redirect
+    // (http->https). We need to invalidate the image and reload it because
+    // mixed content blocker only bails if upgrade-insecure-requests is set on
+    // the doc and the resource load is http: which would result in an incorrect
+    // mixed content warning.
+    nsCOMPtr<nsIDocShell> docShell =
+        NS_CP_GetDocShellFromContext(ToSupports(aLoadingDocument));
+    if (docShell) {
+      Document* document = docShell->GetDocument();
+      if (document && document->GetUpgradeInsecureRequests(false)) {
+        return false;
+      }
+    }
+
+    if (!aTriggeringPrincipal || !aTriggeringPrincipal->IsSystemPrincipal()) {
+      // reset the decision for mixed content blocker check
+      decision = nsIContentPolicy::REJECT_REQUEST;
+      rv = nsMixedContentBlocker::ShouldLoad(insecureRedirect, contentLocation,
+                                             secCheckLoadInfo,
+                                             ""_ns,  // mime guess
+                                             true,   // aReportError
+                                             &decision);
+      if (NS_FAILED(rv) || !NS_CP_ACCEPTED(decision)) {
+        return false;
+      }
+    }
+  }
+
+  return true;
+}
+
+// Returns true if this request is compatible with the given CORS mode on the
+// given loading principal, and false if the request may not be reused due
+// to CORS.
+static bool ValidateCORSMode(imgRequest* aRequest, bool aForcePrincipalCheck,
+                             CORSMode aCORSMode,
+                             nsIPrincipal* aTriggeringPrincipal) {
+  // If the entry's CORS mode doesn't match, or the CORS mode matches but the
+  // document principal isn't the same, we can't use this request.
+  if (aRequest->GetCORSMode() != aCORSMode) {
+    return false;
+  }
+
+  if (aRequest->GetCORSMode() != CORS_NONE || aForcePrincipalCheck) {
+    nsCOMPtr<nsIPrincipal> otherprincipal = aRequest->GetTriggeringPrincipal();
+
+    // If we previously had a principal, but we don't now, we can't use this
+    // request.
+    if (otherprincipal && !aTriggeringPrincipal) {
+      return false;
+    }
+
+    if (otherprincipal && aTriggeringPrincipal &&
+        !otherprincipal->Equals(aTriggeringPrincipal)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+static bool ValidateSecurityInfo(imgRequest* aRequest,
+                                 bool aForcePrincipalCheck, CORSMode aCORSMode,
+                                 nsIPrincipal* aTriggeringPrincipal,
+                                 Document* aLoadingDocument,
+                                 nsContentPolicyType aPolicyType) {
+  if (!ValidateCORSMode(aRequest, aForcePrincipalCheck, aCORSMode,
+                        aTriggeringPrincipal)) {
+    return false;
+  }
+  // Content Policy Check on Cached Images
+  return ShouldLoadCachedImage(aRequest, aLoadingDocument, aTriggeringPrincipal,
+                               aPolicyType,
+                               /* aSendCSPViolationReports */ false);
+}
+
+static nsresult NewImageChannel(
+    nsIChannel** aResult,
+    // If aForcePrincipalCheckForCacheEntry is true, then we will
+    // force a principal check even when not using CORS before
+    // assuming we have a cache hit on a cache entry that we
+    // create for this channel.  This is an out param that should
+    // be set to true if this channel ends up depending on
+    // aTriggeringPrincipal and false otherwise.
+    bool* aForcePrincipalCheckForCacheEntry, nsIURI* aURI,
+    nsIURI* aInitialDocumentURI, CORSMode aCORSMode,
+    nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
+    nsLoadFlags aLoadFlags, nsContentPolicyType aPolicyType,
+    nsIPrincipal* aTriggeringPrincipal, nsINode* aRequestingNode,
+    bool aRespectPrivacy, uint64_t aEarlyHintPreloaderId) {
+  MOZ_ASSERT(aResult);
+
+  nsresult rv;
+  nsCOMPtr<nsIHttpChannel> newHttpChannel;
+
+  nsCOMPtr<nsIInterfaceRequestor> callbacks;
+
+  if (aLoadGroup) {
+    // Get the notification callbacks from the load group for the new channel.
+    //
+    // XXX: This is not exactly correct, because the network request could be
+    //      referenced by multiple windows...  However, the new channel needs
+    //      something.  So, using the 'first' notification callbacks is better
+    //      than nothing...
+    //
+    aLoadGroup->GetNotificationCallbacks(getter_AddRefs(callbacks));
+  }
+
+  // Pass in a nullptr loadgroup because this is the underlying network
+  // request. This request may be referenced by several proxy image requests
+  // (possibly in different documents).
+  // If all of the proxy requests are canceled then this request should be
+  // canceled too.
+  //
+
+  nsSecurityFlags securityFlags =
+      nsContentSecurityManager::ComputeSecurityFlags(
+          aCORSMode, nsContentSecurityManager::CORSSecurityMapping::
+                         CORS_NONE_MAPS_TO_INHERITED_CONTEXT);
+
+  securityFlags |= nsILoadInfo::SEC_ALLOW_CHROME;
+
+  // Note we are calling NS_NewChannelWithTriggeringPrincipal() here with a
+  // node and a principal. This is for things like background images that are
+  // specified by user stylesheets, where the document is being styled, but
+  // the principal is that of the user stylesheet.
+  if (aRequestingNode && aTriggeringPrincipal) {
+    rv = NS_NewChannelWithTriggeringPrincipal(aResult, aURI, aRequestingNode,
+                                              aTriggeringPrincipal,
+                                              securityFlags, aPolicyType,
+                                              nullptr,  // PerformanceStorage
+                                              nullptr,  // loadGroup
+                                              callbacks, aLoadFlags);
+
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    if (aPolicyType == nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON) {
+      // If this is a favicon loading, we will use the originAttributes from the
+      // triggeringPrincipal as the channel's originAttributes. This allows the
+      // favicon loading from XUL will use the correct originAttributes.
+
+      nsCOMPtr<nsILoadInfo> loadInfo = (*aResult)->LoadInfo();
+      rv = loadInfo->SetOriginAttributes(
+          aTriggeringPrincipal->OriginAttributesRef());
+    }
+  } else {
+    // either we are loading something inside a document, in which case
+    // we should always have a requestingNode, or we are loading something
+    // outside a document, in which case the triggeringPrincipal and
+    // triggeringPrincipal should always be the systemPrincipal.
+    // However, there are exceptions: one is Notifications which create a
+    // channel in the parent process in which case we can't get a
+    // requestingNode.
+    rv = NS_NewChannel(aResult, aURI, nsContentUtils::GetSystemPrincipal(),
+                       securityFlags, aPolicyType,
+                       nullptr,  // nsICookieJarSettings
+                       nullptr,  // PerformanceStorage
+                       nullptr,  // loadGroup
+                       callbacks, aLoadFlags);
+
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    // Use the OriginAttributes from the loading principal, if one is available,
+    // and adjust the private browsing ID based on what kind of load the caller
+    // has asked us to perform.
+    OriginAttributes attrs;
+    if (aTriggeringPrincipal) {
+      attrs = aTriggeringPrincipal->OriginAttributesRef();
+    }
+    attrs.mPrivateBrowsingId = aRespectPrivacy ? 1 : 0;
+
+    nsCOMPtr<nsILoadInfo> loadInfo = (*aResult)->LoadInfo();
+    rv = loadInfo->SetOriginAttributes(attrs);
+  }
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  // only inherit if we have a principal
+  *aForcePrincipalCheckForCacheEntry =
+      aTriggeringPrincipal && nsContentUtils::ChannelShouldInheritPrincipal(
+                                  aTriggeringPrincipal, aURI,
+                                  /* aInheritForAboutBlank */ false,
+                                  /* aForceInherit */ false);
+
+  // Initialize HTTP-specific attributes
+  newHttpChannel = do_QueryInterface(*aResult);
+  if (newHttpChannel) {
+    nsCOMPtr<nsIHttpChannelInternal> httpChannelInternal =
+        do_QueryInterface(newHttpChannel);
+    NS_ENSURE_TRUE(httpChannelInternal, NS_ERROR_UNEXPECTED);
+    rv = httpChannelInternal->SetDocumentURI(aInitialDocumentURI);
+    MOZ_ASSERT(NS_SUCCEEDED(rv));
+    if (aReferrerInfo) {
+      DebugOnly<nsresult> rv = newHttpChannel->SetReferrerInfo(aReferrerInfo);
+      MOZ_ASSERT(NS_SUCCEEDED(rv));
+    }
+
+    if (aEarlyHintPreloaderId) {
+      rv = httpChannelInternal->SetEarlyHintPreloaderId(aEarlyHintPreloaderId);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+  }
+
+  // Image channels are loaded by default with reduced priority.
+  nsCOMPtr<nsISupportsPriority> p = do_QueryInterface(*aResult);
+  if (p) {
+    uint32_t priority = nsISupportsPriority::PRIORITY_LOW;
+
+    if (aLoadFlags & nsIRequest::LOAD_BACKGROUND) {
+      ++priority;  // further reduce priority for background loads
+    }
+
+    p->AdjustPriority(priority);
+  }
+
+  // Create a new loadgroup for this new channel, using the old group as
+  // the parent. The indirection keeps the channel insulated from cancels,
+  // but does allow a way for this revalidation to be associated with at
+  // least one base load group for scheduling/caching purposes.
+
+  nsCOMPtr<nsILoadGroup> loadGroup = do_CreateInstance(NS_LOADGROUP_CONTRACTID);
+  nsCOMPtr<nsILoadGroupChild> childLoadGroup = do_QueryInterface(loadGroup);
+  if (childLoadGroup) {
+    childLoadGroup->SetParentLoadGroup(aLoadGroup);
+  }
+  (*aResult)->SetLoadGroup(loadGroup);
+
+  return NS_OK;
+}
+
+static uint32_t SecondsFromPRTime(PRTime aTime) {
+  return nsContentUtils::SecondsFromPRTime(aTime);
+}
+
+/* static */
+imgCacheEntry::imgCacheEntry(imgLoader* loader, imgRequest* request,
+                             bool forcePrincipalCheck)
+    : mLoader(loader),
+      mRequest(request),
+      mDataSize(0),
+      mTouchedTime(SecondsFromPRTime(PR_Now())),
+      mLoadTime(SecondsFromPRTime(PR_Now())),
+      mExpiryTime(0),
+      mMustValidate(false),
+      // We start off as evicted so we don't try to update the cache.
+      // PutIntoCache will set this to false.
+      mEvicted(true),
+      mHasNoProxies(true),
+      mForcePrincipalCheck(forcePrincipalCheck),
+      mHasNotified(false) {}
+
+imgCacheEntry::~imgCacheEntry() {
+  LOG_FUNC(gImgLog, "imgCacheEntry::~imgCacheEntry()");
+}
+
+void imgCacheEntry::Touch(bool updateTime /* = true */) {
+  LOG_SCOPE(gImgLog, "imgCacheEntry::Touch");
+
+  if (updateTime) {
+    mTouchedTime = SecondsFromPRTime(PR_Now());
+  }
+
+  UpdateCache();
+}
+
+void imgCacheEntry::UpdateCache(int32_t diff /* = 0 */) {
+  // Don't update the cache if we've been removed from it or it doesn't care
+  // about our size or usage.
+  if (!Evicted() && HasNoProxies()) {
+    mLoader->CacheEntriesChanged(diff);
+  }
+}
+
+void imgCacheEntry::UpdateLoadTime() {
+  mLoadTime = SecondsFromPRTime(PR_Now());
+}
+
+void imgCacheEntry::SetHasNoProxies(bool hasNoProxies) {
+  if (MOZ_LOG_TEST(gImgLog, LogLevel::Debug)) {
+    if (hasNoProxies) {
+      LOG_FUNC_WITH_PARAM(gImgLog, "imgCacheEntry::SetHasNoProxies true", "uri",
+                          mRequest->CacheKey().URI());
+    } else {
+      LOG_FUNC_WITH_PARAM(gImgLog, "imgCacheEntry::SetHasNoProxies false",
+                          "uri", mRequest->CacheKey().URI());
+    }
+  }
+
+  mHasNoProxies = hasNoProxies;
+}
+
+imgCacheQueue::imgCacheQueue() : mDirty(false), mSize(0) {}
+
+void imgCacheQueue::UpdateSize(int32_t diff) { mSize += diff; }
+
+uint32_t imgCacheQueue::GetSize() const { return mSize; }
+
+void imgCacheQueue::Remove(imgCacheEntry* entry) {
+  uint64_t index = mQueue.IndexOf(entry);
+  if (index == queueContainer::NoIndex) {
+    return;
+  }
+
+  mSize -= mQueue[index]->GetDataSize();
+
+  // If the queue is clean and this is the first entry,
+  // then we can efficiently remove the entry without
+  // dirtying the sort order.
+  if (!IsDirty() && index == 0) {
+    std::pop_heap(mQueue.begin(), mQueue.end(), imgLoader::CompareCacheEntries);
+    mQueue.RemoveLastElement();
+    return;
+  }
+
+  // Remove from the middle of the list.  This potentially
+  // breaks the binary heap sort order.
+  mQueue.RemoveElementAt(index);
+
+  // If we only have one entry or the queue is empty, though,
+  // then the sort order is still effectively good.  Simply
+  // refresh the list to clear the dirty flag.
+  if (mQueue.Length() <= 1) {
+    Refresh();
+    return;
+  }
+
+  // Otherwise we must mark the queue dirty and potentially
+  // trigger an expensive sort later.
+  MarkDirty();
+}
+
+void imgCacheQueue::Push(imgCacheEntry* entry) {
+  mSize += entry->GetDataSize();
+
+  RefPtr<imgCacheEntry> refptr(entry);
+  mQueue.AppendElement(std::move(refptr));
+  // If we're not dirty already, then we can efficiently add this to the
+  // binary heap immediately.  This is only O(log n).
+  if (!IsDirty()) {
+    std::push_heap(mQueue.begin(), mQueue.end(),
+                   imgLoader::CompareCacheEntries);
+  }
+}
+
+already_AddRefed<imgCacheEntry> imgCacheQueue::Pop() {
+  if (mQueue.IsEmpty()) {
+    return nullptr;
+  }
+  if (IsDirty()) {
+    Refresh();
+  }
+
+  std::pop_heap(mQueue.begin(), mQueue.end(), imgLoader::CompareCacheEntries);
+  RefPtr<imgCacheEntry> entry = mQueue.PopLastElement();
+
+  mSize -= entry->GetDataSize();
+  return entry.forget();
+}
+
+void imgCacheQueue::Refresh() {
+  // Resort the list.  This is an O(3 * n) operation and best avoided
+  // if possible.
+  std::make_heap(mQueue.begin(), mQueue.end(), imgLoader::CompareCacheEntries);
+  mDirty = false;
+}
+
+void imgCacheQueue::MarkDirty() { mDirty = true; }
+
+bool imgCacheQueue::IsDirty() { return mDirty; }
+
+uint32_t imgCacheQueue::GetNumElements() const { return mQueue.Length(); }
+
+bool imgCacheQueue::Contains(imgCacheEntry* aEntry) const {
+  return mQueue.Contains(aEntry);
+}
+
+imgCacheQueue::iterator imgCacheQueue::begin() { return mQueue.begin(); }
+
+imgCacheQueue::const_iterator imgCacheQueue::begin() const {
+  return mQueue.begin();
+}
+
+imgCacheQueue::iterator imgCacheQueue::end() { return mQueue.end(); }
+
+imgCacheQueue::const_iterator imgCacheQueue::end() const {
+  return mQueue.end();
+}
+
+nsresult imgLoader::CreateNewProxyForRequest(
+    imgRequest* aRequest, nsIURI* aURI, nsILoadGroup* aLoadGroup,
+    Document* aLoadingDocument, imgINotificationObserver* aObserver,
+    nsLoadFlags aLoadFlags, imgRequestProxy** _retval) {
+  LOG_SCOPE_WITH_PARAM(gImgLog, "imgLoader::CreateNewProxyForRequest",
+                       "imgRequest", aRequest);
+
+  /* XXX If we move decoding onto separate threads, we should save off the
+     calling thread here and pass it off to |proxyRequest| so that it call
+     proxy calls to |aObserver|.
+   */
+
+  RefPtr<imgRequestProxy> proxyRequest = new imgRequestProxy();
+
+  /* It is important to call |SetLoadFlags()| before calling |Init()| because
+     |Init()| adds the request to the loadgroup.
+   */
+  proxyRequest->SetLoadFlags(aLoadFlags);
+
+  // init adds itself to imgRequest's list of observers
+  nsresult rv = proxyRequest->Init(aRequest, aLoadGroup, aLoadingDocument, aURI,
+                                   aObserver);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  proxyRequest.forget(_retval);
+  return NS_OK;
+}
+
+class imgCacheExpirationTracker final
+    : public nsExpirationTracker<imgCacheEntry, 3> {
+  enum { TIMEOUT_SECONDS = 10 };
+
+ public:
+  imgCacheExpirationTracker();
+
+ protected:
+  void NotifyExpired(imgCacheEntry* entry) override;
+};
+
+imgCacheExpirationTracker::imgCacheExpirationTracker()
+    : nsExpirationTracker<imgCacheEntry, 3>(TIMEOUT_SECONDS * 1000,
+                                            "imgCacheExpirationTracker") {}
+
+void imgCacheExpirationTracker::NotifyExpired(imgCacheEntry* entry) {
+  // Hold on to a reference to this entry, because the expiration tracker
+  // mechanism doesn't.
+  RefPtr<imgCacheEntry> kungFuDeathGrip(entry);
+
+  if (MOZ_LOG_TEST(gImgLog, LogLevel::Debug)) {
+    RefPtr<imgRequest> req = entry->GetRequest();
+    if (req) {
+      LOG_FUNC_WITH_PARAM(gImgLog, "imgCacheExpirationTracker::NotifyExpired",
+                          "entry", req->CacheKey().URI());
+    }
+  }
+
+  // We can be called multiple times on the same entry. Don't do work multiple
+  // times.
+  if (!entry->Evicted()) {
+    entry->Loader()->RemoveFromCache(entry);
+  }
+
+  entry->Loader()->VerifyCacheSizes();
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// imgLoader
+///////////////////////////////////////////////////////////////////////////////
+
+double imgLoader::sCacheTimeWeight;
+uint32_t imgLoader::sCacheMaxSize;
+imgMemoryReporter* imgLoader::sMemReporter;
+
+NS_IMPL_ISUPPORTS(imgLoader, imgILoader, nsIContentSniffer, imgICache,
+                  nsISupportsWeakReference, nsIObserver)
+
+static imgLoader* gNormalLoader = nullptr;
+static imgLoader* gPrivateBrowsingLoader = nullptr;
+
+/* static */
+already_AddRefed<imgLoader> imgLoader::CreateImageLoader() {
+  // In some cases, such as xpctests, XPCOM modules are not automatically
+  // initialized.  We need to make sure that our module is initialized before
+  // we hand out imgLoader instances and code starts using them.
+  mozilla::image::EnsureModuleInitialized();
+
+  RefPtr<imgLoader> loader = new imgLoader();
+  loader->Init();
+
+  return loader.forget();
+}
+
+imgLoader* imgLoader::NormalLoader() {
+  if (!gNormalLoader) {
+    gNormalLoader = CreateImageLoader().take();
+  }
+  return gNormalLoader;
+}
+
+imgLoader* imgLoader::PrivateBrowsingLoader() {
+  if (!gPrivateBrowsingLoader) {
+    gPrivateBrowsingLoader = CreateImageLoader().take();
+    gPrivateBrowsingLoader->RespectPrivacyNotifications();
+  }
+  return gPrivateBrowsingLoader;
+}
+
+imgLoader::imgLoader()
+    : mUncachedImagesMutex("imgLoader::UncachedImages"),
+      mRespectPrivacy(false) {
+  sMemReporter->AddRef();
+  sMemReporter->RegisterLoader(this);
+}
+
+imgLoader::~imgLoader() {
+  ClearImageCache();
+  {
+    // If there are any of our imgRequest's left they are in the uncached
+    // images set, so clear their pointer to us.
+    MutexAutoLock lock(mUncachedImagesMutex);
+    for (RefPtr<imgRequest> req : mUncachedImages) {
+      req->ClearLoader();
+    }
+  }
+  sMemReporter->UnregisterLoader(this);
+  sMemReporter->Release();
+}
+
+void imgLoader::VerifyCacheSizes() {
+#ifdef DEBUG
+  if (!mCacheTracker) {
+    return;
+  }
+
+  uint32_t cachesize = mCache.Count();
+  uint32_t queuesize = mCacheQueue.GetNumElements();
+  uint32_t trackersize = 0;
+  for (nsExpirationTracker<imgCacheEntry, 3>::Iterator it(mCacheTracker.get());
+       it.Next();) {
+    trackersize++;
+  }
+  MOZ_ASSERT(queuesize == trackersize, "Queue and tracker sizes out of sync!");
+  MOZ_ASSERT(queuesize <= cachesize, "Queue has more elements than cache!");
+#endif
+}
+
+void imgLoader::GlobalInit() {
+  sCacheTimeWeight = StaticPrefs::image_cache_timeweight_AtStartup() / 1000.0;
+  int32_t cachesize = StaticPrefs::image_cache_size_AtStartup();
+  sCacheMaxSize = cachesize > 0 ? cachesize : 0;
+
+  sMemReporter = new imgMemoryReporter();
+  RegisterStrongAsyncMemoryReporter(sMemReporter);
+  RegisterImagesContentUsedUncompressedDistinguishedAmount(
+      imgMemoryReporter::ImagesContentUsedUncompressedDistinguishedAmount);
+}
+
+void imgLoader::ShutdownMemoryReporter() {
+  UnregisterImagesContentUsedUncompressedDistinguishedAmount();
+  UnregisterStrongMemoryReporter(sMemReporter);
+}
+
+nsresult imgLoader::InitCache() {
+  nsCOMPtr<nsIObserverService> os = mozilla::services::GetObserverService();
+  if (!os) {
+    return NS_ERROR_FAILURE;
+  }
+
+  os->AddObserver(this, "memory-pressure", false);
+  os->AddObserver(this, "chrome-flush-caches", false);
+  os->AddObserver(this, "last-pb-context-exited", false);
+  os->AddObserver(this, "profile-before-change", false);
+  os->AddObserver(this, "xpcom-shutdown", false);
+
+  mCacheTracker = MakeUnique<imgCacheExpirationTracker>();
+
+  return NS_OK;
+}
+
+nsresult imgLoader::Init() {
+  InitCache();
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+imgLoader::RespectPrivacyNotifications() {
+  mRespectPrivacy = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+imgLoader::Observe(nsISupports* aSubject, const char* aTopic,
+                   const char16_t* aData) {
+  if (strcmp(aTopic, "memory-pressure") == 0) {
+    MinimizeCache();
+  } else if (strcmp(aTopic, "chrome-flush-caches") == 0) {
+    MinimizeCache();
+    ClearImageCache({ClearOption::ChromeOnly});
+  } else if (strcmp(aTopic, "last-pb-context-exited") == 0) {
+    if (mRespectPrivacy) {
+      ClearImageCache();
+    }
+  } else if (strcmp(aTopic, "profile-before-change") == 0) {
+    mCacheTracker = nullptr;
+  } else if (strcmp(aTopic, "xpcom-shutdown") == 0) {
+    mCacheTracker = nullptr;
+    ShutdownMemoryReporter();
+
+  } else {
+    // (Nothing else should bring us here)
+    MOZ_ASSERT(0, "Invalid topic received");
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+imgLoader::ClearCache(bool chrome) {
+  if (XRE_IsParentProcess()) {
+    bool privateLoader = this == gPrivateBrowsingLoader;
+    for (auto* cp : ContentParent::AllProcesses(ContentParent::eLive)) {
+      Unused << cp->SendClearImageCache(privateLoader, chrome);
+    }
+  }
+  ClearOptions options;
+  if (chrome) {
+    options += ClearOption::ChromeOnly;
+  }
+  return ClearImageCache(options);
+}
+
+NS_IMETHODIMP
+imgLoader::RemoveEntriesFromPrincipalInAllProcesses(nsIPrincipal* aPrincipal) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  for (auto* cp : ContentParent::AllProcesses(ContentParent::eLive)) {
+    Unused << cp->SendClearImageCacheFromPrincipal(aPrincipal);
+  }
+
+  imgLoader* loader;
+  if (aPrincipal->OriginAttributesRef().mPrivateBrowsingId ==
+      nsIScriptSecurityManager::DEFAULT_PRIVATE_BROWSING_ID) {
+    loader = imgLoader::NormalLoader();
+  } else {
+    loader = imgLoader::PrivateBrowsingLoader();
+  }
+
+  return loader->RemoveEntriesInternal(aPrincipal, nullptr);
+}
+
+NS_IMETHODIMP
+imgLoader::RemoveEntriesFromBaseDomainInAllProcesses(
+    const nsACString& aBaseDomain) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  for (auto* cp : ContentParent::AllProcesses(ContentParent::eLive)) {
+    Unused << cp->SendClearImageCacheFromBaseDomain(aBaseDomain);
+  }
+
+  return RemoveEntriesInternal(nullptr, &aBaseDomain);
+}
+
+nsresult imgLoader::RemoveEntriesInternal(nsIPrincipal* aPrincipal,
+                                          const nsACString* aBaseDomain) {
+  // Can only clear by either principal or base domain.
+  if ((!aPrincipal && !aBaseDomain) || (aPrincipal && aBaseDomain)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsAutoString origin;
+  if (aPrincipal) {
+    nsresult rv = nsContentUtils::GetUTFOrigin(aPrincipal, origin);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  nsCOMPtr<nsIEffectiveTLDService> tldService;
+  AutoTArray<RefPtr<imgCacheEntry>, 128> entriesToBeRemoved;
+
+  // For base domain we only clear the non-chrome cache.
+  for (const auto& entry : mCache) {
+    const auto& key = entry.GetKey();
+
+    const bool shouldRemove = [&] {
+      if (aPrincipal) {
+        if (key.OriginAttributesRef() !=
+            BasePrincipal::Cast(aPrincipal)->OriginAttributesRef()) {
+          return false;
+        }
+
+        nsAutoString imageOrigin;
+        nsresult rv = nsContentUtils::GetUTFOrigin(key.URI(), imageOrigin);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return false;
+        }
+
+        return imageOrigin == origin;
+      }
+
+      if (!aBaseDomain) {
+        return false;
+      }
+      // Clear by baseDomain.
+      nsAutoCString host;
+      nsresult rv = key.URI()->GetHost(host);
+      if (NS_FAILED(rv) || host.IsEmpty()) {
+        return false;
+      }
+
+      if (!tldService) {
+        tldService = do_GetService(NS_EFFECTIVETLDSERVICE_CONTRACTID);
+      }
+      if (NS_WARN_IF(!tldService)) {
+        return false;
+      }
+
+      bool hasRootDomain = false;
+      rv = tldService->HasRootDomain(host, *aBaseDomain, &hasRootDomain);
+      if (NS_SUCCEEDED(rv) && hasRootDomain) {
+        return true;
+      }
+
+      // If we don't get a direct base domain match, also check for cache of
+      // third parties partitioned under aBaseDomain.
+
+      // The isolation key is either just the base domain, or an origin suffix
+      // which contains the partitionKey holding the baseDomain.
+
+      if (key.IsolationKeyRef().Equals(*aBaseDomain)) {
+        return true;
+      }
+
+      // The isolation key does not match the given base domain. It may be an
+      // origin suffix. Parse it into origin attributes.
+      OriginAttributes attrs;
+      if (!attrs.PopulateFromSuffix(key.IsolationKeyRef())) {
+        // Key is not an origin suffix.
+        return false;
+      }
+
+      return StoragePrincipalHelper::PartitionKeyHasBaseDomain(
+          attrs.mPartitionKey, *aBaseDomain);
+    }();
+
+    if (shouldRemove) {
+      entriesToBeRemoved.AppendElement(entry.GetData());
+    }
+  }
+
+  for (auto& entry : entriesToBeRemoved) {
+    if (!RemoveFromCache(entry)) {
+      NS_WARNING(
+          "Couldn't remove an entry from the cache in "
+          "RemoveEntriesInternal()\n");
+    }
+  }
+
+  return NS_OK;
+}
+
+constexpr auto AllCORSModes() {
+  return MakeInclusiveEnumeratedRange(kFirstCORSMode, kLastCORSMode);
+}
+
+NS_IMETHODIMP
+imgLoader::RemoveEntry(nsIURI* aURI, Document* aDoc) {
+  if (!aURI) {
+    return NS_OK;
+  }
+  OriginAttributes attrs;
+  if (aDoc) {
+    attrs = aDoc->NodePrincipal()->OriginAttributesRef();
+  }
+  for (auto corsMode : AllCORSModes()) {
+    ImageCacheKey key(aURI, corsMode, attrs, aDoc);
+    RemoveFromCache(key);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+imgLoader::FindEntryProperties(nsIURI* uri, Document* aDoc,
+                               nsIProperties** _retval) {
+  *_retval = nullptr;
+
+  OriginAttributes attrs;
+  if (aDoc) {
+    nsCOMPtr<nsIPrincipal> principal = aDoc->NodePrincipal();
+    if (principal) {
+      attrs = principal->OriginAttributesRef();
+    }
+  }
+
+  for (auto corsMode : AllCORSModes()) {
+    ImageCacheKey key(uri, corsMode, attrs, aDoc);
+    RefPtr<imgCacheEntry> entry;
+    if (!mCache.Get(key, getter_AddRefs(entry)) || !entry) {
+      continue;
+    }
+    if (mCacheTracker && entry->HasNoProxies()) {
+      mCacheTracker->MarkUsed(entry);
+    }
+    RefPtr<imgRequest> request = entry->GetRequest();
+    if (request) {
+      nsCOMPtr<nsIProperties> properties = request->Properties();
+      properties.forget(_retval);
+      return NS_OK;
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP_(void)
+imgLoader::ClearCacheForControlledDocument(Document* aDoc) {
+  MOZ_ASSERT(aDoc);
+  AutoTArray<RefPtr<imgCacheEntry>, 128> entriesToBeRemoved;
+  for (const auto& entry : mCache) {
+    const auto& key = entry.GetKey();
+    if (key.ControlledDocument() == aDoc) {
+      entriesToBeRemoved.AppendElement(entry.GetData());
+    }
+  }
+  for (auto& entry : entriesToBeRemoved) {
+    if (!RemoveFromCache(entry)) {
+      NS_WARNING(
+          "Couldn't remove an entry from the cache in "
+          "ClearCacheForControlledDocument()\n");
+    }
+  }
+}
+
+void imgLoader::Shutdown() {
+  NS_IF_RELEASE(gNormalLoader);
+  gNormalLoader = nullptr;
+  NS_IF_RELEASE(gPrivateBrowsingLoader);
+  gPrivateBrowsingLoader = nullptr;
+}
+
+bool imgLoader::PutIntoCache(const ImageCacheKey& aKey, imgCacheEntry* entry) {
+  LOG_STATIC_FUNC_WITH_PARAM(gImgLog, "imgLoader::PutIntoCache", "uri",
+                             aKey.URI());
+
+  // Check to see if this request already exists in the cache. If so, we'll
+  // replace the old version.
+  RefPtr<imgCacheEntry> tmpCacheEntry;
+  if (mCache.Get(aKey, getter_AddRefs(tmpCacheEntry)) && tmpCacheEntry) {
+    MOZ_LOG(
+        gImgLog, LogLevel::Debug,
+        ("[this=%p] imgLoader::PutIntoCache -- Element already in the cache",
+         nullptr));
+    RefPtr<imgRequest> tmpRequest = tmpCacheEntry->GetRequest();
+
+    // If it already exists, and we're putting the same key into the cache, we
+    // should remove the old version.
+    MOZ_LOG(gImgLog, LogLevel::Debug,
+            ("[this=%p] imgLoader::PutIntoCache -- Replacing cached element",
+             nullptr));
+
+    RemoveFromCache(aKey);
+  } else {
+    MOZ_LOG(gImgLog, LogLevel::Debug,
+            ("[this=%p] imgLoader::PutIntoCache --"
+             " Element NOT already in the cache",
+             nullptr));
+  }
+
+  mCache.InsertOrUpdate(aKey, RefPtr{entry});
+
+  // We can be called to resurrect an evicted entry.
+  if (entry->Evicted()) {
+    entry->SetEvicted(false);
+  }
+
+  // If we're resurrecting an entry with no proxies, put it back in the
+  // tracker and queue.
+  if (entry->HasNoProxies()) {
+    nsresult addrv = NS_OK;
+
+    if (mCacheTracker) {
+      addrv = mCacheTracker->AddObject(entry);
+    }
+
+    if (NS_SUCCEEDED(addrv)) {
+      mCacheQueue.Push(entry);
+    }
+  }
+
+  RefPtr<imgRequest> request = entry->GetRequest();
+  request->SetIsInCache(true);
+  RemoveFromUncachedImages(request);
+
+  return true;
+}
+
+bool imgLoader::SetHasNoProxies(imgRequest* aRequest, imgCacheEntry* aEntry) {
+  LOG_STATIC_FUNC_WITH_PARAM(gImgLog, "imgLoader::SetHasNoProxies", "uri",
+                             aRequest->CacheKey().URI());
+
+  aEntry->SetHasNoProxies(true);
+
+  if (aEntry->Evicted()) {
+    return false;
+  }
+
+  nsresult addrv = NS_OK;
+
+  if (mCacheTracker) {
+    addrv = mCacheTracker->AddObject(aEntry);
+  }
+
+  if (NS_SUCCEEDED(addrv)) {
+    mCacheQueue.Push(aEntry);
+  }
+
+  return true;
+}
+
+bool imgLoader::SetHasProxies(imgRequest* aRequest) {
+  VerifyCacheSizes();
+
+  const ImageCacheKey& key = aRequest->CacheKey();
+
+  LOG_STATIC_FUNC_WITH_PARAM(gImgLog, "imgLoader::SetHasProxies", "uri",
+                             key.URI());
+
+  RefPtr<imgCacheEntry> entry;
+  if (mCache.Get(key, getter_AddRefs(entry)) && entry) {
+    // Make sure the cache entry is for the right request
+    RefPtr<imgRequest> entryRequest = entry->GetRequest();
+    if (entryRequest == aRequest && entry->HasNoProxies()) {
+      mCacheQueue.Remove(entry);
+
+      if (mCacheTracker) {
+        mCacheTracker->RemoveObject(entry);
+      }
+
+      entry->SetHasNoProxies(false);
+
+      return true;
+    }
+  }
+
+  return false;
+}
+
+void imgLoader::CacheEntriesChanged(int32_t aSizeDiff /* = 0 */) {
+  // We only need to dirty the queue if there is any sorting
+  // taking place.  Empty or single-entry lists can't become
+  // dirty.
+  if (mCacheQueue.GetNumElements() > 1) {
+    mCacheQueue.MarkDirty();
+  }
+  mCacheQueue.UpdateSize(aSizeDiff);
+}
+
+void imgLoader::CheckCacheLimits() {
+  if (mCacheQueue.GetNumElements() == 0) {
+    NS_ASSERTION(mCacheQueue.GetSize() == 0,
+                 "imgLoader::CheckCacheLimits -- incorrect cache size");
+  }
+
+  // Remove entries from the cache until we're back at our desired max size.
+  while (mCacheQueue.GetSize() > sCacheMaxSize) {
+    // Remove the first entry in the queue.
+    RefPtr<imgCacheEntry> entry(mCacheQueue.Pop());
+
+    NS_ASSERTION(entry, "imgLoader::CheckCacheLimits -- NULL entry pointer");
+
+    if (MOZ_LOG_TEST(gImgLog, LogLevel::Debug)) {
+      RefPtr<imgRequest> req = entry->GetRequest();
+      if (req) {
+        LOG_STATIC_FUNC_WITH_PARAM(gImgLog, "imgLoader::CheckCacheLimits",
+                                   "entry", req->CacheKey().URI());
+      }
+    }
+
+    if (entry) {
+      // We just popped this entry from the queue, so pass AlreadyRemoved
+      // to avoid searching the queue again in RemoveFromCache.
+      RemoveFromCache(entry, QueueState::AlreadyRemoved);
+    }
+  }
+}
+
+bool imgLoader::ValidateRequestWithNewChannel(
+    imgRequest* request, nsIURI* aURI, nsIURI* aInitialDocumentURI,
+    nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
+    imgINotificationObserver* aObserver, Document* aLoadingDocument,
+    uint64_t aInnerWindowId, nsLoadFlags aLoadFlags,
+    nsContentPolicyType aLoadPolicyType, imgRequestProxy** aProxyRequest,
+    nsIPrincipal* aTriggeringPrincipal, CORSMode aCORSMode, bool aLinkPreload,
+    uint64_t aEarlyHintPreloaderId, bool* aNewChannelCreated) {
+  // now we need to insert a new channel request object in between the real
+  // request and the proxy that basically delays loading the image until it
+  // gets a 304 or figures out that this needs to be a new request
+
+  nsresult rv;
+
+  // If we're currently in the middle of validating this request, just hand
+  // back a proxy to it; the required work will be done for us.
+  if (imgCacheValidator* validator = request->GetValidator()) {
+    rv = CreateNewProxyForRequest(request, aURI, aLoadGroup, aLoadingDocument,
+                                  aObserver, aLoadFlags, aProxyRequest);
+    if (NS_FAILED(rv)) {
+      return false;
+    }
+
+    if (*aProxyRequest) {
+      imgRequestProxy* proxy = static_cast<imgRequestProxy*>(*aProxyRequest);
+
+      // We will send notifications from imgCacheValidator::OnStartRequest().
+      // In the mean time, we must defer notifications because we are added to
+      // the imgRequest's proxy list, and we can get extra notifications
+      // resulting from methods such as StartDecoding(). See bug 579122.
+      proxy->MarkValidating();
+
+      if (aLinkPreload) {
+        MOZ_ASSERT(aLoadingDocument);
+        proxy->PrioritizeAsPreload();
+        auto preloadKey = PreloadHashKey::CreateAsImage(
+            aURI, aTriggeringPrincipal, aCORSMode);
+        proxy->NotifyOpen(preloadKey, aLoadingDocument, true);
+      }
+
+      // Attach the proxy without notifying
+      validator->AddProxy(proxy);
+    }
+
+    return true;
+  }
+  // We will rely on Necko to cache this request when it's possible, and to
+  // tell imgCacheValidator::OnStartRequest whether the request came from its
+  // cache.
+  nsCOMPtr<nsIChannel> newChannel;
+  bool forcePrincipalCheck;
+  rv =
+      NewImageChannel(getter_AddRefs(newChannel), &forcePrincipalCheck, aURI,
+                      aInitialDocumentURI, aCORSMode, aReferrerInfo, aLoadGroup,
+                      aLoadFlags, aLoadPolicyType, aTriggeringPrincipal,
+                      aLoadingDocument, mRespectPrivacy, aEarlyHintPreloaderId);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  if (aNewChannelCreated) {
+    *aNewChannelCreated = true;
+  }
+
+  RefPtr<imgRequestProxy> req;
+  rv = CreateNewProxyForRequest(request, aURI, aLoadGroup, aLoadingDocument,
+                                aObserver, aLoadFlags, getter_AddRefs(req));
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  // Make sure that OnStatus/OnProgress calls have the right request set...
+  RefPtr<nsProgressNotificationProxy> progressproxy =
+      new nsProgressNotificationProxy(newChannel, req);
+  if (!progressproxy) {
+    return false;
+  }
+
+  RefPtr<imgCacheValidator> hvc =
+      new imgCacheValidator(progressproxy, this, request, aLoadingDocument,
+                            aInnerWindowId, forcePrincipalCheck);
+
+  // Casting needed here to get past multiple inheritance.
+  nsCOMPtr<nsIStreamListener> listener =
+      do_QueryInterface(static_cast<nsIThreadRetargetableStreamListener*>(hvc));
+  NS_ENSURE_TRUE(listener, false);
+
+  // We must set the notification callbacks before setting up the
+  // CORS listener, because that's also interested inthe
+  // notification callbacks.
+  newChannel->SetNotificationCallbacks(hvc);
+
+  request->SetValidator(hvc);
+
+  // We will send notifications from imgCacheValidator::OnStartRequest().
+  // In the mean time, we must defer notifications because we are added to
+  // the imgRequest's proxy list, and we can get extra notifications
+  // resulting from methods such as StartDecoding(). See bug 579122.
+  req->MarkValidating();
+
+  if (aLinkPreload) {
+    MOZ_ASSERT(aLoadingDocument);
+    req->PrioritizeAsPreload();
+    auto preloadKey =
+        PreloadHashKey::CreateAsImage(aURI, aTriggeringPrincipal, aCORSMode);
+    req->NotifyOpen(preloadKey, aLoadingDocument, true);
+  }
+
+  // Add the proxy without notifying
+  hvc->AddProxy(req);
+
+  mozilla::net::PredictorLearn(aURI, aInitialDocumentURI,
+                               nsINetworkPredictor::LEARN_LOAD_SUBRESOURCE,
+                               aLoadGroup);
+  rv = newChannel->AsyncOpen(listener);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    req->CancelAndForgetObserver(rv);
+    // This will notify any current or future <link preload> tags.  Pass the
+    // non-open channel so that we can read loadinfo and referrer info of that
+    // channel.
+    req->NotifyStart(newChannel);
+    // Use the non-channel overload of this method to force the notification to
+    // happen.  The preload request has not been assigned a channel.
+    req->NotifyStop(rv);
+    return false;
+  }
+
+  req.forget(aProxyRequest);
+  return true;
+}
+
+void imgLoader::NotifyObserversForCachedImage(
+    imgCacheEntry* aEntry, imgRequest* request, nsIURI* aURI,
+    nsIReferrerInfo* aReferrerInfo, Document* aLoadingDocument,
+    nsIPrincipal* aTriggeringPrincipal, CORSMode aCORSMode,
+    uint64_t aEarlyHintPreloaderId) {
+  if (aEntry->HasNotified()) {
+    return;
+  }
+
+  nsCOMPtr<nsIObserverService> obsService = services::GetObserverService();
+
+  if (!obsService->HasObservers("http-on-image-cache-response")) {
+    return;
+  }
+
+  aEntry->SetHasNotified();
+
+  nsCOMPtr<nsIChannel> newChannel;
+  bool forcePrincipalCheck;
+  nsresult rv = NewImageChannel(
+      getter_AddRefs(newChannel), &forcePrincipalCheck, aURI, nullptr,
+      aCORSMode, aReferrerInfo, nullptr, 0,
+      nsIContentPolicy::TYPE_INTERNAL_IMAGE, aTriggeringPrincipal,
+      aLoadingDocument, mRespectPrivacy, aEarlyHintPreloaderId);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+
+  RefPtr<HttpBaseChannel> httpBaseChannel = do_QueryObject(newChannel);
+  if (httpBaseChannel) {
+    httpBaseChannel->SetDummyChannelForImageCache();
+    newChannel->SetContentType(nsDependentCString(request->GetMimeType()));
+    RefPtr<mozilla::image::Image> image = request->GetImage();
+    if (image) {
+      newChannel->SetContentLength(aEntry->GetDataSize());
+    }
+    obsService->NotifyObservers(newChannel, "http-on-image-cache-response",
+                                nullptr);
+  }
+}
+
+bool imgLoader::ValidateEntry(
+    imgCacheEntry* aEntry, nsIURI* aURI, nsIURI* aInitialDocumentURI,
+    nsIReferrerInfo* aReferrerInfo, nsILoadGroup* aLoadGroup,
+    imgINotificationObserver* aObserver, Document* aLoadingDocument,
+    nsLoadFlags aLoadFlags, nsContentPolicyType aLoadPolicyType,
+    bool aCanMakeNewChannel, bool* aNewChannelCreated,
+    imgRequestProxy** aProxyRequest, nsIPrincipal* aTriggeringPrincipal,
+    CORSMode aCORSMode, bool aLinkPreload, uint64_t aEarlyHintPreloaderId) {
+  LOG_SCOPE(gImgLog, "imgLoader::ValidateEntry");
+
+  // If the expiration time is zero, then the request has not gotten far enough
+  // to know when it will expire, or we know it will never expire (see
+  // nsContentUtils::GetSubresourceCacheValidationInfo).
+  uint32_t expiryTime = aEntry->GetExpiryTime();
+  bool hasExpired = expiryTime && expiryTime <= SecondsFromPRTime(PR_Now());
+
+  nsresult rv;
+
+  // Special treatment for file URLs - aEntry has expired if file has changed
+  nsCOMPtr<nsIFileURL> fileUrl(do_QueryInterface(aURI));
+  if (fileUrl) {
+    uint32_t lastModTime = aEntry->GetLoadTime();
+
+    nsCOMPtr<nsIFile> theFile;
+    rv = fileUrl->GetFile(getter_AddRefs(theFile));
+    if (NS_SUCCEEDED(rv)) {
+      PRTime fileLastMod;
+      rv = theFile->GetLastModifiedTime(&fileLastMod);
+      if (NS_SUCCEEDED(rv)) {
+        // nsIFile uses millisec, NSPR usec
+        fileLastMod *= 1000;
+        hasExpired = SecondsFromPRTime((PRTime)fileLastMod) > lastModTime;
+      }
+    }
+  }
+
+  RefPtr<imgRequest> request(aEntry->GetRequest());
+
+  if (!request) {
+    return false;
+  }
+
+  if (!ValidateSecurityInfo(request, aEntry->ForcePrincipalCheck(), aCORSMode,
+                            aTriggeringPrincipal, aLoadingDocument,
+                            aLoadPolicyType)) {
+    return false;
+  }
+
+  // data URIs are immutable and by their nature can't leak data, so we can
+  // just return true in that case.  Doing so would mean that shift-reload
+  // doesn't reload data URI documents/images though (which is handy for
+  // debugging during gecko development) so we make an exception in that case.
+  if (aURI->SchemeIs("data") && !(aLoadFlags & nsIRequest::LOAD_BYPASS_CACHE)) {
+    return true;
+  }
+
+  bool validateRequest = false;
+
+  if (!request->CanReuseWithoutValidation(aLoadingDocument)) {
+    // If we would need to revalidate this entry, but we're being told to
+    // bypass the cache, we don't allow this entry to be used.
+    if (aLoadFlags & nsIRequest::LOAD_BYPASS_CACHE) {
+      return false;
+    }
+
+    if (MOZ_UNLIKELY(ChaosMode::isActive(ChaosFeature::ImageCache))) {
+      if (ChaosMode::randomUint32LessThan(4) < 1) {
+        return false;
+      }
+    }
+
+    // Determine whether the cache aEntry must be revalidated...
+    validateRequest = ShouldRevalidateEntry(aEntry, aLoadFlags, hasExpired);
+
+    MOZ_LOG(gImgLog, LogLevel::Debug,
+            ("imgLoader::ValidateEntry validating cache entry. "
+             "validateRequest = %d",
+             validateRequest));
+  } else if (!aLoadingDocument && MOZ_LOG_TEST(gImgLog, LogLevel::Debug)) {
+    MOZ_LOG(gImgLog, LogLevel::Debug,
+            ("imgLoader::ValidateEntry BYPASSING cache validation for %s "
+             "because of NULL loading document",
+             aURI->GetSpecOrDefault().get()));
+  }
+
+  // If the original request is still transferring don't kick off a validation
+  // network request because it is a bit silly to issue a validation request if
+  // the original request hasn't even finished yet. So just return true
+  // indicating the caller can create a new proxy for the request and use it as
+  // is.
+  // This is an optimization but it's also required for correctness. If we don't
+  // do this then when firing the load complete notification for the original
+  // request that can unblock load for the document and then spin the event loop
+  // (see the stack in bug 1641682) which then the OnStartRequest for the
+  // validation request can fire which can call UpdateProxies and can sync
+  // notify on the progress tracker about all existing state, which includes
+  // load complete, so we fire a second load complete notification for the
+  // image.
+  // In addition, we want to validate if the original request encountered
+  // an error for two reasons. The first being if the error was a network error
+  // then trying to re-fetch the image might succeed. The second is more
+  // complicated. We decide if we should fire the load or error event for img
+  // elements depending on if the image has error in its status at the time when
+  // the load complete notification is received, and we set error status on an
+  // image if it encounters a network error or a decode error with no real way
+  // to tell them apart. So if we load an image that will produce a decode error
+  // the first time we will usually fire the load event, and then decode enough
+  // to encounter the decode error and set the error status on the image. The
+  // next time we reference the image in the same document the load complete
+  // notification is replayed and this time the error status from the decode is
+  // already present so we fire the error event instead of the load event. This
+  // is a bug (bug 1645576) that we should fix. In order to avoid that bug in
+  // some cases (specifically the cases when we hit this code and try to
+  // validate the request) we make sure to validate. This avoids the bug because
+  // when the load complete notification arrives the proxy is marked as
+  // validating so it lies about its status and returns nothing.
+  bool requestComplete = false;
+  RefPtr<ProgressTracker> tracker;
+  RefPtr<mozilla::image::Image> image = request->GetImage();
+  if (image) {
+    tracker = image->GetProgressTracker();
+  } else {
+    tracker = request->GetProgressTracker();
+  }
+  if (tracker) {
+    if (tracker->GetProgress() & (FLAG_LOAD_COMPLETE | FLAG_HAS_ERROR)) {
+      requestComplete = true;
+    }
+  }
+  if (!requestComplete) {
+    return true;
+  }
+
+  if (validateRequest && aCanMakeNewChannel) {
+    LOG_SCOPE(gImgLog, "imgLoader::ValidateRequest |cache hit| must validate");
+
+    uint64_t innerWindowID =
+        aLoadingDocument ? aLoadingDocument->InnerWindowID() : 0;
+    return ValidateRequestWithNewChannel(
+        request, aURI, aInitialDocumentURI, aReferrerInfo, aLoadGroup,
+        aObserver, aLoadingDocument, innerWindowID, aLoadFlags, aLoadPolicyType,
+        aProxyRequest, aTriggeringPrincipal, aCORSMode, aLinkPreload,
+        aEarlyHintPreloaderId, aNewChannelCreated);
+  }
+
+  if (!validateRequest) {
+    NotifyObserversForCachedImage(aEntry, request, aURI, aReferrerInfo,
+                                  aLoadingDocument, aTriggeringPrincipal,
+                                  aCORSMode, aEarlyHintPreloaderId);
+  }
+
+  return !validateRequest;
+}
+
+bool imgLoader::RemoveFromCache(const ImageCacheKey& aKey) {
+  LOG_STATIC_FUNC_WITH_PARAM(gImgLog, "imgLoader::RemoveFromCache", "uri",
+                             aKey.URI());
+  RefPtr<imgCacheEntry> entry;
+  mCache.Remove(aKey, getter_AddRefs(entry));
+  if (entry) {
+    MOZ_ASSERT(!entry->Evicted(), "Evicting an already-evicted cache entry!");
+
+    // Entries with no proxies are in the tracker.
+    if (entry->HasNoProxies()) {
+      if (mCacheTracker) {
+        mCacheTracker->RemoveObject(entry);
+      }
+      mCacheQueue.Remove(entry);
+    }
+
+    entry->SetEvicted(true);
+
+    RefPtr<imgRequest> request = entry->GetRequest();
+    request->SetIsInCache(false);
+    AddToUncachedImages(request);
+
+    return true;
+  }
+  return false;
+}
+
+bool imgLoader::RemoveFromCache(imgCacheEntry* entry, QueueState aQueueState) {
+  LOG_STATIC_FUNC(gImgLog, "imgLoader::RemoveFromCache entry");
+
+  RefPtr<imgRequest> request = entry->GetRequest();
+  if (request) {
+    const ImageCacheKey& key = request->CacheKey();
+    LOG_STATIC_FUNC_WITH_PARAM(gImgLog, "imgLoader::RemoveFromCache",
+                               "entry's uri", key.URI());
+
+    mCache.Remove(key);
+
+    if (entry->HasNoProxies()) {
+      LOG_STATIC_FUNC(gImgLog,
+                      "imgLoader::RemoveFromCache removing from tracker");
+      if (mCacheTracker) {
+        mCacheTracker->RemoveObject(entry);
+      }
+      // Only search the queue to remove the entry if its possible it might
+      // be in the queue.  If we know its not in the queue this would be
+      // wasted work.
+      MOZ_ASSERT_IF(aQueueState == QueueState::AlreadyRemoved,
+                    !mCacheQueue.Contains(entry));
+      if (aQueueState == QueueState::MaybeExists) {
+        mCacheQueue.Remove(entry);
+      }
+    }
+
+    entry->SetEvicted(true);
+    request->SetIsInCache(false);
+    AddToUncachedImages(request);
+
+    return true;
+  }
+
+  return false;
+}
+
+nsresult imgLoader::ClearImageCache(ClearOptions aOptions) {
+  const bool chromeOnly = aOptions.contains(ClearOption::ChromeOnly);
+  const auto ShouldRemove = [&](imgCacheEntry* aEntry) {
+    if (chromeOnly) {
+      // TODO: Consider also removing "resource://" etc?
+      RefPtr<imgRequest> request = aEntry->GetRequest();
+      if (!request || !request->CacheKey().URI()->SchemeIs("chrome")) {
+        return false;
+      }
+    }
+    return true;
+  };
+  if (aOptions.contains(ClearOption::UnusedOnly)) {
+    LOG_STATIC_FUNC(gImgLog, "imgLoader::ClearImageCache queue");
+    // We have to make a temporary, since RemoveFromCache removes the element
+    // from the queue, invalidating iterators.
+    nsTArray<RefPtr<imgCacheEntry>> entries(mCacheQueue.GetNumElements());
+    for (auto& entry : mCacheQueue) {
+      if (ShouldRemove(entry)) {
+        entries.AppendElement(entry);
+      }
+    }
+
+    // Iterate in reverse order to minimize array copying.
+    for (auto& entry : entries) {
+      if (!RemoveFromCache(entry)) {
+        return NS_ERROR_FAILURE;
+      }
+    }
+
+    MOZ_ASSERT(chromeOnly || mCacheQueue.GetNumElements() == 0);
+    return NS_OK;
+  }
+
+  LOG_STATIC_FUNC(gImgLog, "imgLoader::ClearImageCache table");
+  // We have to make a temporary, since RemoveFromCache removes the element
+  // from the queue, invalidating iterators.
+  const auto entries =
+      ToTArray<nsTArray<RefPtr<imgCacheEntry>>>(mCache.Values());
+  for (const auto& entry : entries) {
+    if (!ShouldRemove(entry)) {
+      continue;
+    }
+    if (!RemoveFromCache(entry)) {
+      return NS_ERROR_FAILURE;
+    }
+  }
+  MOZ_ASSERT(chromeOnly || mCache.IsEmpty());
+  return NS_OK;
+}
+
+void imgLoader::AddToUncachedImages(imgRequest* aRequest) {
+  MutexAutoLock lock(mUncachedImagesMutex);
+  mUncachedImages.Insert(aRequest);
+}
+
+void imgLoader::RemoveFromUncachedImages(imgRequest* aRequest) {
+  MutexAutoLock lock(mUncachedImagesMutex);
+  mUncachedImages.Remove(aRequest);
+}
+
+#define LOAD_FLAGS_CACHE_MASK \
+  (nsIRequest::LOAD_BYPASS_CACHE | nsIRequest::LOAD_FROM_CACHE)
+
+#define LOAD_FLAGS_VALIDATE_MASK                              \
+  (nsIRequest::VALIDATE_ALWAYS | nsIRequest::VALIDATE_NEVER | \
+   nsIRequest::VALIDATE_ONCE_PER_SESSION)
+
+NS_IMETHODIMP
+imgLoader::LoadImageXPCOM(
+    nsIURI* aURI, nsIURI* aInitialDocumentURI, nsIReferrerInfo* aReferrerInfo,
+    nsIPrincipal* aTriggeringPrincipal, nsILoadGroup* aLoadGroup,
+    imgINotificationObserver* aObserver, Document* aLoadingDocument,
+    nsLoadFlags aLoadFlags, nsISupports* aCacheKey,
+    nsContentPolicyType aContentPolicyType, imgIRequest** _retval) {
+  // Optional parameter, so defaults to 0 (== TYPE_INVALID)
+  if (!aContentPolicyType) {
+    aContentPolicyType = nsIContentPolicy::TYPE_INTERNAL_IMAGE;
+  }
+  imgRequestProxy* proxy;
+  nsresult rv =
+      LoadImage(aURI, aInitialDocumentURI, aReferrerInfo, aTriggeringPrincipal,
+                0, aLoadGroup, aObserver, aLoadingDocument, aLoadingDocument,
+                aLoadFlags, aCacheKey, aContentPolicyType, u""_ns,
+                /* aUseUrgentStartForChannel */ false, /* aListPreload */ false,
+                0, &proxy);
+  *_retval = proxy;
+  return rv;
+}
+
+static void MakeRequestStaticIfNeeded(
+    Document* aLoadingDocument, imgRequestProxy** aProxyAboutToGetReturned) {
+  if (!aLoadingDocument || !aLoadingDocument->IsStaticDocument()) {
+    return;
+  }
+
+  if (!*aProxyAboutToGetReturned) {
+    return;
+  }
+
+  RefPtr<imgRequestProxy> proxy = dont_AddRef(*aProxyAboutToGetReturned);
+  *aProxyAboutToGetReturned = nullptr;
+
+  RefPtr<imgRequestProxy> staticProxy =
+      proxy->GetStaticRequest(aLoadingDocument);
+  if (staticProxy != proxy) {
+    proxy->CancelAndForgetObserver(NS_BINDING_ABORTED);
+    proxy = std::move(staticProxy);
+  }
+  proxy.forget(aProxyAboutToGetReturned);
+}
+
+bool imgLoader::IsImageAvailable(nsIURI* aURI,
+                                 nsIPrincipal* aTriggeringPrincipal,
+                                 CORSMode aCORSMode, Document* aDocument) {
+  ImageCacheKey key(aURI, aCORSMode,
+                    aTriggeringPrincipal->OriginAttributesRef(), aDocument);
+  RefPtr<imgCacheEntry> entry;
+  if (!mCache.Get(key, getter_AddRefs(entry)) || !entry) {
+    return false;
+  }
+  RefPtr<imgRequest> request = entry->GetRequest();
+  if (!request) {
+    return false;
+  }
+  if (nsCOMPtr<nsILoadGroup> docLoadGroup = aDocument->GetDocumentLoadGroup()) {
+    nsLoadFlags requestFlags = nsIRequest::LOAD_NORMAL;
+    docLoadGroup->GetLoadFlags(&requestFlags);
+    if (requestFlags & nsIRequest::LOAD_BYPASS_CACHE) {
+      // If we're bypassing the cache, treat the image as not available.
+      return false;
+    }
+  }
+  return ValidateCORSMode(request, false, aCORSMode, aTriggeringPrincipal);
+}
+
+nsresult imgLoader::LoadImage(
+    nsIURI* aURI, nsIURI* aInitialDocumentURI, nsIReferrerInfo* aReferrerInfo,
+    nsIPrincipal* aTriggeringPrincipal, uint64_t aRequestContextID,
+    nsILoadGroup* aLoadGroup, imgINotificationObserver* aObserver,
+    nsINode* aContext, Document* aLoadingDocument, nsLoadFlags aLoadFlags,
+    nsISupports* aCacheKey, nsContentPolicyType aContentPolicyType,
+    const nsAString& initiatorType, bool aUseUrgentStartForChannel,
+    bool aLinkPreload, uint64_t aEarlyHintPreloaderId,
+    imgRequestProxy** _retval) {
+  VerifyCacheSizes();
+
+  NS_ASSERTION(aURI, "imgLoader::LoadImage -- NULL URI pointer");
+
+  if (!aURI) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto makeStaticIfNeeded = mozilla::MakeScopeExit(
+      [&] { MakeRequestStaticIfNeeded(aLoadingDocument, _retval); });
+
+  AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING("imgLoader::LoadImage", NETWORK,
+                                        aURI->GetSpecOrDefault());
+
+  LOG_SCOPE_WITH_PARAM(gImgLog, "imgLoader::LoadImage", "aURI", aURI);
+
+  *_retval = nullptr;
+
+  RefPtr<imgRequest> request;
+
+  nsresult rv;
+  nsLoadFlags requestFlags = nsIRequest::LOAD_NORMAL;
+
+#ifdef DEBUG
+  bool isPrivate = false;
+
+  if (aLoadingDocument) {
+    isPrivate = nsContentUtils::IsInPrivateBrowsing(aLoadingDocument);
+  } else if (aLoadGroup) {
+    isPrivate = nsContentUtils::IsInPrivateBrowsing(aLoadGroup);
+  }
+  MOZ_ASSERT(isPrivate == mRespectPrivacy);
+
+  if (aLoadingDocument) {
+    // The given load group should match that of the document if given. If
+    // that isn't the case, then we need to add more plumbing to ensure we
+    // block the document as well.
+    nsCOMPtr<nsILoadGroup> docLoadGroup =
+        aLoadingDocument->GetDocumentLoadGroup();
+    MOZ_ASSERT(docLoadGroup == aLoadGroup);
+  }
+#endif
+
+  // Get the default load flags from the loadgroup (if possible)...
+  if (aLoadGroup) {
+    aLoadGroup->GetLoadFlags(&requestFlags);
+  }
+  //
+  // Merge the default load flags with those passed in via aLoadFlags.
+  // Currently, *only* the caching, validation and background load flags
+  // are merged...
+  //
+  // The flags in aLoadFlags take precedence over the default flags!
+  //
+  if (aLoadFlags & LOAD_FLAGS_CACHE_MASK) {
+    // Override the default caching flags...
+    requestFlags = (requestFlags & ~LOAD_FLAGS_CACHE_MASK) |
+                   (aLoadFlags & LOAD_FLAGS_CACHE_MASK);
+  }
+  if (aLoadFlags & LOAD_FLAGS_VALIDATE_MASK) {
+    // Override the default validation flags...
+    requestFlags = (requestFlags & ~LOAD_FLAGS_VALIDATE_MASK) |
+                   (aLoadFlags & LOAD_FLAGS_VALIDATE_MASK);
+  }
+  if (aLoadFlags & nsIRequest::LOAD_BACKGROUND) {
+    // Propagate background loading...
+    requestFlags |= nsIRequest::LOAD_BACKGROUND;
+  }
+  if (aLoadFlags & nsIRequest::LOAD_RECORD_START_REQUEST_DELAY) {
+    requestFlags |= nsIRequest::LOAD_RECORD_START_REQUEST_DELAY;
+  }
+
+  if (aLinkPreload) {
+    // Set background loading if it is <link rel=preload>
+    requestFlags |= nsIRequest::LOAD_BACKGROUND;
+  }
+
+  CORSMode corsmode = CORS_NONE;
+  if (aLoadFlags & imgILoader::LOAD_CORS_ANONYMOUS) {
+    corsmode = CORS_ANONYMOUS;
+  } else if (aLoadFlags & imgILoader::LOAD_CORS_USE_CREDENTIALS) {
+    corsmode = CORS_USE_CREDENTIALS;
+  }
+
+  // Look in the preloaded images of loading document first.
+  if (StaticPrefs::network_preload() && !aLinkPreload && aLoadingDocument) {
+    // All Early Hints preloads are Link preloads, therefore we don't have a
+    // Early Hints preload here
+    MOZ_ASSERT(!aEarlyHintPreloaderId);
+    auto key =
+        PreloadHashKey::CreateAsImage(aURI, aTriggeringPrincipal, corsmode);
+    if (RefPtr<PreloaderBase> preload =
+            aLoadingDocument->Preloads().LookupPreload(key)) {
+      RefPtr<imgRequestProxy> proxy = do_QueryObject(preload);
+      MOZ_ASSERT(proxy);
+
+      MOZ_LOG(gImgLog, LogLevel::Debug,
+              ("[this=%p] imgLoader::LoadImage -- preloaded [proxy=%p]"
+               " [document=%p]\n",
+               this, proxy.get(), aLoadingDocument));
+
+      // Removing the preload for this image to be in parity with Chromium.  Any
+      // following regular image request will be reloaded using the regular
+      // path: image cache, http cache, network.  Any following `<link
+      // rel=preload as=image>` will start a new image preload that can be
+      // satisfied from http cache or network.
+      //
+      // There is a spec discussion for "preload cache", see
+      // https://github.com/w3c/preload/issues/97. And it is also not clear how
+      // preload image interacts with list of available images, see
+      // https://github.com/whatwg/html/issues/4474.
+      proxy->RemoveSelf(aLoadingDocument);
+      proxy->NotifyUsage(aLoadingDocument);
+
+      imgRequest* request = proxy->GetOwner();
+      nsresult rv =
+          CreateNewProxyForRequest(request, aURI, aLoadGroup, aLoadingDocument,
+                                   aObserver, requestFlags, _retval);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      imgRequestProxy* newProxy = *_retval;
+      if (imgCacheValidator* validator = request->GetValidator()) {
+        newProxy->MarkValidating();
+        // Attach the proxy without notifying and this will add us to the load
+        // group.
+        validator->AddProxy(newProxy);
+      } else {
+        // It's OK to add here even if the request is done. If it is, it'll send
+        // a OnStopRequest()and the proxy will be removed from the loadgroup in
+        // imgRequestProxy::OnLoadComplete.
+        newProxy->AddToLoadGroup();
+        newProxy->NotifyListener();
+      }
+
+      return NS_OK;
+    }
+  }
+
+  RefPtr<imgCacheEntry> entry;
+
+  // Look in the cache for our URI, and then validate it.
+  // XXX For now ignore aCacheKey. We will need it in the future
+  // for correctly dealing with image load requests that are a result
+  // of post data.
+  OriginAttributes attrs;
+  if (aTriggeringPrincipal) {
+    attrs = aTriggeringPrincipal->OriginAttributesRef();
+  }
+  ImageCacheKey key(aURI, corsmode, attrs, aLoadingDocument);
+  if (mCache.Get(key, getter_AddRefs(entry)) && entry) {
+    bool newChannelCreated = false;
+    if (ValidateEntry(entry, aURI, aInitialDocumentURI, aReferrerInfo,
+                      aLoadGroup, aObserver, aLoadingDocument, requestFlags,
+                      aContentPolicyType, true, &newChannelCreated, _retval,
+                      aTriggeringPrincipal, corsmode, aLinkPreload,
+                      aEarlyHintPreloaderId)) {
+      request = entry->GetRequest();
+
+      // If this entry has no proxies, its request has no reference to the
+      // entry.
+      if (entry->HasNoProxies()) {
+        LOG_FUNC_WITH_PARAM(gImgLog,
+                            "imgLoader::LoadImage() adding proxyless entry",
+                            "uri", key.URI());
+        MOZ_ASSERT(!request->HasCacheEntry(),
+                   "Proxyless entry's request has cache entry!");
+        request->SetCacheEntry(entry);
+
+        if (mCacheTracker && entry->GetExpirationState()->IsTracked()) {
+          mCacheTracker->MarkUsed(entry);
+        }
+      }
+
+      entry->Touch();
+
+      if (!newChannelCreated) {
+        // This is ugly but it's needed to report CSP violations. We have 3
+        // scenarios:
+        // - we don't have cache. We are not in this if() stmt. A new channel is
+        //   created and that triggers the CSP checks.
+        // - We have a cache entry and this is blocked by CSP directives.
+        DebugOnly<bool> shouldLoad = ShouldLoadCachedImage(
+            request, aLoadingDocument, aTriggeringPrincipal, aContentPolicyType,
+            /* aSendCSPViolationReports */ true);
+        MOZ_ASSERT(shouldLoad);
+      }
+    } else {
+      // We can't use this entry. We'll try to load it off the network, and if
+      // successful, overwrite the old entry in the cache with a new one.
+      entry = nullptr;
+    }
+  }
+
+  // Keep the channel in this scope, so we can adjust its notificationCallbacks
+  // later when we create the proxy.
+  nsCOMPtr<nsIChannel> newChannel;
+  // If we didn't get a cache hit, we need to load from the network.
+  if (!request) {
+    LOG_SCOPE(gImgLog, "imgLoader::LoadImage |cache miss|");
+
+    bool forcePrincipalCheck;
+    rv = NewImageChannel(getter_AddRefs(newChannel), &forcePrincipalCheck, aURI,
+                         aInitialDocumentURI, corsmode, aReferrerInfo,
+                         aLoadGroup, requestFlags, aContentPolicyType,
+                         aTriggeringPrincipal, aContext, mRespectPrivacy,
+                         aEarlyHintPreloaderId);
+    if (NS_FAILED(rv)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    MOZ_ASSERT(NS_UsePrivateBrowsing(newChannel) == mRespectPrivacy);
+
+    NewRequestAndEntry(forcePrincipalCheck, this, key, getter_AddRefs(request),
+                       getter_AddRefs(entry));
+
+    MOZ_LOG(gImgLog, LogLevel::Debug,
+            ("[this=%p] imgLoader::LoadImage -- Created new imgRequest"
+             " [request=%p]\n",
+             this, request.get()));
+
+    nsCOMPtr<nsIClassOfService> cos(do_QueryInterface(newChannel));
+    if (cos) {
+      if (aUseUrgentStartForChannel && !aLinkPreload) {
+        cos->AddClassFlags(nsIClassOfService::UrgentStart);
+      }
+
+      if (StaticPrefs::network_http_tailing_enabled() &&
+          aContentPolicyType == nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON) {
+        cos->AddClassFlags(nsIClassOfService::Throttleable |
+                           nsIClassOfService::Tail);
+        nsCOMPtr<nsIHttpChannel> httpChannel(do_QueryInterface(newChannel));
+        if (httpChannel) {
+          Unused << httpChannel->SetRequestContextID(aRequestContextID);
+        }
+      }
+    }
+
+    nsCOMPtr<nsILoadGroup> channelLoadGroup;
+    newChannel->GetLoadGroup(getter_AddRefs(channelLoadGroup));
+    rv = request->Init(aURI, aURI, /* aHadInsecureRedirect = */ false,
+                       channelLoadGroup, newChannel, entry, aLoadingDocument,
+                       aTriggeringPrincipal, corsmode, aReferrerInfo);
+    if (NS_FAILED(rv)) {
+      return NS_ERROR_FAILURE;
+    }
+
+    // Add the initiator type for this image load
+    nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(newChannel);
+    if (timedChannel) {
+      timedChannel->SetInitiatorType(initiatorType);
+    }
+
+    // create the proxy listener
+    nsCOMPtr<nsIStreamListener> listener = new ProxyListener(request.get());
+
+    MOZ_LOG(gImgLog, LogLevel::Debug,
+            ("[this=%p] imgLoader::LoadImage -- Calling channel->AsyncOpen()\n",
+             this));
+
+    mozilla::net::PredictorLearn(aURI, aInitialDocumentURI,
+                                 nsINetworkPredictor::LEARN_LOAD_SUBRESOURCE,
+                                 aLoadGroup);
+
+    nsresult openRes;
+    openRes = newChannel->AsyncOpen(listener);
+
+    if (NS_FAILED(openRes)) {
+      MOZ_LOG(
+          gImgLog, LogLevel::Debug,
+          ("[this=%p] imgLoader::LoadImage -- AsyncOpen() failed: 0x%" PRIx32
+           "\n",
+           this, static_cast<uint32_t>(openRes)));
+      request->CancelAndAbort(openRes);
+      return openRes;
+    }
+
+    // Try to add the new request into the cache.
+    PutIntoCache(key, entry);
+  } else {
+    LOG_MSG_WITH_PARAM(gImgLog, "imgLoader::LoadImage |cache hit|", "request",
+                       request);
+  }
+
+  // If we didn't get a proxy when validating the cache entry, we need to
+  // create one.
+  if (!*_retval) {
+    // ValidateEntry() has three return values: "Is valid," "might be valid --
+    // validating over network", and "not valid." If we don't have a _retval,
+    // we know ValidateEntry is not validating over the network, so it's safe
+    // to SetLoadId here because we know this request is valid for this context.
+    //
+    // Note, however, that this doesn't guarantee the behaviour we want (one
+    // URL maps to the same image on a page) if we load the same image in a
+    // different tab (see bug 528003), because its load id will get re-set, and
+    // that'll cause us to validate over the network.
+    request->SetLoadId(aLoadingDocument);
+
+    LOG_MSG(gImgLog, "imgLoader::LoadImage", "creating proxy request.");
+    rv = CreateNewProxyForRequest(request, aURI, aLoadGroup, aLoadingDocument,
+                                  aObserver, requestFlags, _retval);
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    imgRequestProxy* proxy = *_retval;
+
+    // Make sure that OnStatus/OnProgress calls have the right request set, if
+    // we did create a channel here.
+    if (newChannel) {
+      nsCOMPtr<nsIInterfaceRequestor> requestor(
+          new nsProgressNotificationProxy(newChannel, proxy));
+      if (!requestor) {
+        return NS_ERROR_OUT_OF_MEMORY;
+      }
+      newChannel->SetNotificationCallbacks(requestor);
+    }
+
+    if (aLinkPreload) {
+      MOZ_ASSERT(aLoadingDocument);
+      proxy->PrioritizeAsPreload();
+      auto preloadKey =
+          PreloadHashKey::CreateAsImage(aURI, aTriggeringPrincipal, corsmode);
+      proxy->NotifyOpen(preloadKey, aLoadingDocument, true);
+    }
+
+    // Note that it's OK to add here even if the request is done.  If it is,
+    // it'll send a OnStopRequest() to the proxy in imgRequestProxy::Notify and
+    // the proxy will be removed from the loadgroup.
+    proxy->AddToLoadGroup();
+
+    // If we're loading off the network, explicitly don't notify our proxy,
+    // because necko (or things called from necko, such as imgCacheValidator)
+    // are going to call our notifications asynchronously, and we can't make it
+    // further asynchronous because observers might rely on imagelib completing
+    // its work between the channel's OnStartRequest and OnStopRequest.
+    if (!newChannel) {
+      proxy->NotifyListener();
+    }
+
+    return rv;
+  }
+
+  NS_ASSERTION(*_retval, "imgLoader::LoadImage -- no return value");
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+imgLoader::LoadImageWithChannelXPCOM(nsIChannel* channel,
+                                     imgINotificationObserver* aObserver,
+                                     Document* aLoadingDocument,
+                                     nsIStreamListener** listener,
+                                     imgIRequest** _retval) {
+  nsresult result;
+  imgRequestProxy* proxy;
+  result = LoadImageWithChannel(channel, aObserver, aLoadingDocument, listener,
+                                &proxy);
+  *_retval = proxy;
+  return result;
+}
+
+nsresult imgLoader::LoadImageWithChannel(nsIChannel* channel,
+                                         imgINotificationObserver* aObserver,
+                                         Document* aLoadingDocument,
+                                         nsIStreamListener** listener,
+                                         imgRequestProxy** _retval) {
+  NS_ASSERTION(channel,
+               "imgLoader::LoadImageWithChannel -- NULL channel pointer");
+
+  MOZ_ASSERT(NS_UsePrivateBrowsing(channel) == mRespectPrivacy);
+
+  auto makeStaticIfNeeded = mozilla::MakeScopeExit(
+      [&] { MakeRequestStaticIfNeeded(aLoadingDocument, _retval); });
+
+  LOG_SCOPE(gImgLog, "imgLoader::LoadImageWithChannel");
+  RefPtr<imgRequest> request;
+
+  nsCOMPtr<nsIURI> uri;
+  channel->GetURI(getter_AddRefs(uri));
+
+  NS_ENSURE_TRUE(channel, NS_ERROR_FAILURE);
+  nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+
+  OriginAttributes attrs = loadInfo->GetOriginAttributes();
+
+  // TODO: Get a meaningful cors mode from the caller probably?
+  const auto corsMode = CORS_NONE;
+  ImageCacheKey key(uri, corsMode, attrs, aLoadingDocument);
+
+  nsLoadFlags requestFlags = nsIRequest::LOAD_NORMAL;
+  channel->GetLoadFlags(&requestFlags);
+
+  RefPtr<imgCacheEntry> entry;
+
+  if (requestFlags & nsIRequest::LOAD_BYPASS_CACHE) {
+    RemoveFromCache(key);
+  } else {
+    // Look in the cache for our URI, and then validate it.
+    // XXX For now ignore aCacheKey. We will need it in the future
+    // for correctly dealing with image load requests that are a result
+    // of post data.
+    if (mCache.Get(key, getter_AddRefs(entry)) && entry) {
+      // We don't want to kick off another network load. So we ask
+      // ValidateEntry to only do validation without creating a new proxy. If
+      // it says that the entry isn't valid any more, we'll only use the entry
+      // we're getting if the channel is loading from the cache anyways.
+      //
+      // XXX -- should this be changed? it's pretty much verbatim from the old
+      // code, but seems nonsensical.
+      //
+      // Since aCanMakeNewChannel == false, we don't need to pass content policy
+      // type/principal/etc
+
+      nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+      // if there is a loadInfo, use the right contentType, otherwise
+      // default to the internal image type
+      nsContentPolicyType policyType = loadInfo->InternalContentPolicyType();
+
+      if (ValidateEntry(entry, uri, nullptr, nullptr, nullptr, aObserver,
+                        aLoadingDocument, requestFlags, policyType, false,
+                        nullptr, nullptr, nullptr, corsMode, false, 0)) {
+        request = entry->GetRequest();
+      } else {
+        nsCOMPtr<nsICacheInfoChannel> cacheChan(do_QueryInterface(channel));
+        bool bUseCacheCopy;
+
+        if (cacheChan) {
+          cacheChan->IsFromCache(&bUseCacheCopy);
+        } else {
+          bUseCacheCopy = false;
+        }
+
+        if (!bUseCacheCopy) {
+          entry = nullptr;
+        } else {
+          request = entry->GetRequest();
+        }
+      }
+
+      if (request && entry) {
+        // If this entry has no proxies, its request has no reference to
+        // the entry.
+        if (entry->HasNoProxies()) {
+          LOG_FUNC_WITH_PARAM(
+              gImgLog,
+              "imgLoader::LoadImageWithChannel() adding proxyless entry", "uri",
+              key.URI());
+          MOZ_ASSERT(!request->HasCacheEntry(),
+                     "Proxyless entry's request has cache entry!");
+          request->SetCacheEntry(entry);
+
+          if (mCacheTracker && entry->GetExpirationState()->IsTracked()) {
+            mCacheTracker->MarkUsed(entry);
+          }
+        }
+      }
+    }
+  }
+
+  nsCOMPtr<nsILoadGroup> loadGroup;
+  channel->GetLoadGroup(getter_AddRefs(loadGroup));
+
+#ifdef DEBUG
+  if (aLoadingDocument) {
+    // The load group of the channel should always match that of the
+    // document if given. If that isn't the case, then we need to add more
+    // plumbing to ensure we block the document as well.
+    nsCOMPtr<nsILoadGroup> docLoadGroup =
+        aLoadingDocument->GetDocumentLoadGroup();
+    MOZ_ASSERT(docLoadGroup == loadGroup);
+  }
+#endif
+
+  // Filter out any load flags not from nsIRequest
+  requestFlags &= nsIRequest::LOAD_REQUESTMASK;
+
+  nsresult rv = NS_OK;
+  if (request) {
+    // we have this in our cache already.. cancel the current (document) load
+
+    // this should fire an OnStopRequest
+    channel->Cancel(NS_ERROR_PARSED_DATA_CACHED);
+
+    *listener = nullptr;  // give them back a null nsIStreamListener
+
+    rv = CreateNewProxyForRequest(request, uri, loadGroup, aLoadingDocument,
+                                  aObserver, requestFlags, _retval);
+    static_cast<imgRequestProxy*>(*_retval)->NotifyListener();
+  } else {
+    // We use originalURI here to fulfil the imgIRequest contract on GetURI.
+    nsCOMPtr<nsIURI> originalURI;
+    channel->GetOriginalURI(getter_AddRefs(originalURI));
+
+    // XXX(seth): We should be able to just use |key| here, except that |key| is
+    // constructed above with the *current URI* and not the *original URI*. I'm
+    // pretty sure this is a bug, and it's preventing us from ever getting a
+    // cache hit in LoadImageWithChannel when redirects are involved.
+    ImageCacheKey originalURIKey(originalURI, corsMode, attrs,
+                                 aLoadingDocument);
+
+    // Default to doing a principal check because we don't know who
+    // started that load and whether their principal ended up being
+    // inherited on the channel.
+    NewRequestAndEntry(/* aForcePrincipalCheckForCacheEntry = */ true, this,
+                       originalURIKey, getter_AddRefs(request),
+                       getter_AddRefs(entry));
+
+    // No principal specified here, because we're not passed one.
+    // In LoadImageWithChannel, the redirects that may have been
+    // associated with this load would have gone through necko.
+    // We only have the final URI in ImageLib and hence don't know
+    // if the request went through insecure redirects.  But if it did,
+    // the necko cache should have handled that (since all necko cache hits
+    // including the redirects will go through content policy).  Hence, we
+    // can set aHadInsecureRedirect to false here.
+    rv = request->Init(originalURI, uri, /* aHadInsecureRedirect = */ false,
+                       channel, channel, entry, aLoadingDocument, nullptr,
+                       corsMode, nullptr);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    RefPtr<ProxyListener> pl =
+        new ProxyListener(static_cast<nsIStreamListener*>(request.get()));
+    pl.forget(listener);
+
+    // Try to add the new request into the cache.
+    PutIntoCache(originalURIKey, entry);
+
+    rv = CreateNewProxyForRequest(request, originalURI, loadGroup,
+                                  aLoadingDocument, aObserver, requestFlags,
+                                  _retval);
+
+    // Explicitly don't notify our proxy, because we're loading off the
+    // network, and necko (or things called from necko, such as
+    // imgCacheValidator) are going to call our notifications asynchronously,
+    // and we can't make it further asynchronous because observers might rely
+    // on imagelib completing its work between the channel's OnStartRequest and
+    // OnStopRequest.
+  }
+
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  (*_retval)->AddToLoadGroup();
+  return rv;
+}
+
+bool imgLoader::SupportImageWithMimeType(const nsACString& aMimeType,
+                                         AcceptedMimeTypes aAccept
+                                         /* = AcceptedMimeTypes::IMAGES */) {
+  nsAutoCString mimeType(aMimeType);
+  ToLowerCase(mimeType);
+
+  if (aAccept == AcceptedMimeTypes::IMAGES_AND_DOCUMENTS &&
+      mimeType.EqualsLiteral("image/svg+xml")) {
+    return true;
+  }
+
+  DecoderType type = DecoderFactory::GetDecoderType(mimeType.get());
+  return type != DecoderType::UNKNOWN;
+}
+
+NS_IMETHODIMP
+imgLoader::GetMIMETypeFromContent(nsIRequest* aRequest,
+                                  const uint8_t* aContents, uint32_t aLength,
+                                  nsACString& aContentType) {
+  nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+  if (channel) {
+    nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo();
+    if (loadInfo->GetSkipContentSniffing()) {
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+  }
+
+  nsresult rv =
+      GetMimeTypeFromContent((const char*)aContents, aLength, aContentType);
+  if (NS_SUCCEEDED(rv) && channel && XRE_IsParentProcess()) {
+    if (RefPtr<mozilla::net::nsHttpChannel> httpChannel =
+            do_QueryObject(channel)) {
+      // If the image type pattern matching algorithm given bytes does not
+      // return undefined, then disable the further check and allow the
+      // response.
+      httpChannel->DisableIsOpaqueResponseAllowedAfterSniffCheck(
+          mozilla::net::nsHttpChannel::SnifferType::Image);
+    }
+  }
+
+  return rv;
+}
+
+/* static */
+nsresult imgLoader::GetMimeTypeFromContent(const char* aContents,
+                                           uint32_t aLength,
+                                           nsACString& aContentType) {
+  nsAutoCString detected;
+
+  /* Is it a GIF? */
+  if (aLength >= 6 &&
+      (!strncmp(aContents, "GIF87a", 6) || !strncmp(aContents, "GIF89a", 6))) {
+    aContentType.AssignLiteral(IMAGE_GIF);
+
+    /* or a PNG? */
+  } else if (aLength >= 8 && ((unsigned char)aContents[0] == 0x89 &&
+                              (unsigned char)aContents[1] == 0x50 &&
+                              (unsigned char)aContents[2] == 0x4E &&
+                              (unsigned char)aContents[3] == 0x47 &&
+                              (unsigned char)aContents[4] == 0x0D &&
+                              (unsigned char)aContents[5] == 0x0A &&
+                              (unsigned char)aContents[6] == 0x1A &&
+                              (unsigned char)aContents[7] == 0x0A)) {
+    aContentType.AssignLiteral(IMAGE_PNG);
+
+    /* maybe a JPEG (JFIF)? */
+    /* JFIF files start with SOI APP0 but older files can start with SOI DQT
+     * so we test for SOI followed by any marker, i.e. FF D8 FF
+     * this will also work for SPIFF JPEG files if they appear in the future.
+     *
+     * (JFIF is 0XFF 0XD8 0XFF 0XE0 <skip 2> 0X4A 0X46 0X49 0X46 0X00)
+     */
+  } else if (aLength >= 3 && ((unsigned char)aContents[0]) == 0xFF &&
+             ((unsigned char)aContents[1]) == 0xD8 &&
+             ((unsigned char)aContents[2]) == 0xFF) {
+    aContentType.AssignLiteral(IMAGE_JPEG);
+
+    /* or how about ART? */
+    /* ART begins with JG (4A 47). Major version offset 2.
+     * Minor version offset 3. Offset 4 must be nullptr.
+     */
+  } else if (aLength >= 5 && ((unsigned char)aContents[0]) == 0x4a &&
+             ((unsigned char)aContents[1]) == 0x47 &&
+             ((unsigned char)aContents[4]) == 0x00) {
+    aContentType.AssignLiteral(IMAGE_ART);
+
+  } else if (aLength >= 2 && !strncmp(aContents, "BM", 2)) {
+    aContentType.AssignLiteral(IMAGE_BMP);
+
+    // ICOs always begin with a 2-byte 0 followed by a 2-byte 1.
+    // CURs begin with 2-byte 0 followed by 2-byte 2.
+  } else if (aLength >= 4 && (!memcmp(aContents, "\000\000\001\000", 4) ||
+                              !memcmp(aContents, "\000\000\002\000", 4))) {
+    aContentType.AssignLiteral(IMAGE_ICO);
+
+    // WebPs always begin with RIFF, a 32-bit length, and WEBP.
+  } else if (aLength >= 12 && !memcmp(aContents, "RIFF", 4) &&
+             !memcmp(aContents + 8, "WEBP", 4)) {
+    aContentType.AssignLiteral(IMAGE_WEBP);
+
+  } else if (MatchesMP4(reinterpret_cast<const uint8_t*>(aContents), aLength,
+                        detected) &&
+             detected.Equals(IMAGE_AVIF)) {
+    aContentType.AssignLiteral(IMAGE_AVIF);
+  } else if ((aLength >= 2 && !memcmp(aContents, "\xFF\x0A", 2)) ||
+             (aLength >= 12 &&
+              !memcmp(aContents, "\x00\x00\x00\x0CJXL \x0D\x0A\x87\x0A", 12))) {
+    // Each version is for containerless and containerful files respectively.
+    aContentType.AssignLiteral(IMAGE_JXL);
+  } else {
+    /* none of the above?  I give up */
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  return NS_OK;
+}
+
+/**
+ * proxy stream listener class used to handle multipart/x-mixed-replace
+ */
+
+#include "nsIRequest.h"
+#include "nsIStreamConverterService.h"
+
+NS_IMPL_ISUPPORTS(ProxyListener, nsIStreamListener,
+                  nsIThreadRetargetableStreamListener, nsIRequestObserver)
+
+ProxyListener::ProxyListener(nsIStreamListener* dest) : mDestListener(dest) {}
+
+ProxyListener::~ProxyListener() = default;
+
+/** nsIRequestObserver methods **/
+
+NS_IMETHODIMP
+ProxyListener::OnStartRequest(nsIRequest* aRequest) {
+  if (!mDestListener) {
+    return NS_ERROR_FAILURE;
+  }
+
+  nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+  if (channel) {
+    // We need to set the initiator type for the image load
+    nsCOMPtr<nsITimedChannel> timedChannel = do_QueryInterface(channel);
+    if (timedChannel) {
+      nsAutoString type;
+      timedChannel->GetInitiatorType(type);
+      if (type.IsEmpty()) {
+        timedChannel->SetInitiatorType(u"img"_ns);
+      }
+    }
+
+    nsAutoCString contentType;
+    nsresult rv = channel->GetContentType(contentType);
+
+    if (!contentType.IsEmpty()) {
+      /* If multipart/x-mixed-replace content, we'll insert a MIME decoder
+         in the pipeline to handle the content and pass it along to our
+         original listener.
+       */
+      if ("multipart/x-mixed-replace"_ns.Equals(contentType)) {
+        nsCOMPtr<nsIStreamConverterService> convServ(
+            do_GetService("@mozilla.org/streamConverters;1", &rv));
+        if (NS_SUCCEEDED(rv)) {
+          nsCOMPtr<nsIStreamListener> toListener(mDestListener);
+          nsCOMPtr<nsIStreamListener> fromListener;
+
+          rv = convServ->AsyncConvertData("multipart/x-mixed-replace", "*/*",
+                                          toListener, nullptr,
+                                          getter_AddRefs(fromListener));
+          if (NS_SUCCEEDED(rv)) {
+            mDestListener = fromListener;
+          }
+        }
+      }
+    }
+  }
+
+  return mDestListener->OnStartRequest(aRequest);
+}
+
+NS_IMETHODIMP
+ProxyListener::OnStopRequest(nsIRequest* aRequest, nsresult status) {
+  if (!mDestListener) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return mDestListener->OnStopRequest(aRequest, status);
+}
+
+/** nsIStreamListener methods **/
+
+NS_IMETHODIMP
+ProxyListener::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* inStr,
+                               uint64_t sourceOffset, uint32_t count) {
+  if (!mDestListener) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return mDestListener->OnDataAvailable(aRequest, inStr, sourceOffset, count);
+}
+
+/** nsThreadRetargetableStreamListener methods **/
+NS_IMETHODIMP
+ProxyListener::CheckListenerChain() {
+  NS_ASSERTION(NS_IsMainThread(), "Should be on the main thread!");
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+      do_QueryInterface(mDestListener, &rv);
+  if (retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+  }
+  MOZ_LOG(
+      gImgLog, LogLevel::Debug,
+      ("ProxyListener::CheckListenerChain %s [this=%p listener=%p rv=%" PRIx32
+       "]",
+       (NS_SUCCEEDED(rv) ? "success" : "failure"), this,
+       (nsIStreamListener*)mDestListener, static_cast<uint32_t>(rv)));
+  return rv;
+}
+
+/**
+ * http validate class.  check a channel for a 304
+ */
+
+NS_IMPL_ISUPPORTS(imgCacheValidator, nsIStreamListener, nsIRequestObserver,
+                  nsIThreadRetargetableStreamListener, nsIChannelEventSink,
+                  nsIInterfaceRequestor, nsIAsyncVerifyRedirectCallback)
+
+imgCacheValidator::imgCacheValidator(nsProgressNotificationProxy* progress,
+                                     imgLoader* loader, imgRequest* request,
+                                     Document* aDocument,
+                                     uint64_t aInnerWindowId,
+                                     bool forcePrincipalCheckForCacheEntry)
+    : mProgressProxy(progress),
+      mRequest(request),
+      mDocument(aDocument),
+      mInnerWindowId(aInnerWindowId),
+      mImgLoader(loader),
+      mHadInsecureRedirect(false) {
+  NewRequestAndEntry(forcePrincipalCheckForCacheEntry, loader,
+                     mRequest->CacheKey(), getter_AddRefs(mNewRequest),
+                     getter_AddRefs(mNewEntry));
+}
+
+imgCacheValidator::~imgCacheValidator() {
+  if (mRequest) {
+    // If something went wrong, and we never unblocked the requests waiting on
+    // validation, now is our last chance. We will cancel the new request and
+    // switch the waiting proxies to it.
+    UpdateProxies(/* aCancelRequest */ true, /* aSyncNotify */ false);
+  }
+}
+
+void imgCacheValidator::AddProxy(imgRequestProxy* aProxy) {
+  // aProxy needs to be in the loadgroup since we're validating from
+  // the network.
+  aProxy->AddToLoadGroup();
+
+  mProxies.AppendElement(aProxy);
+}
+
+void imgCacheValidator::RemoveProxy(imgRequestProxy* aProxy) {
+  mProxies.RemoveElement(aProxy);
+}
+
+void imgCacheValidator::UpdateProxies(bool aCancelRequest, bool aSyncNotify) {
+  MOZ_ASSERT(mRequest);
+
+  // Clear the validator before updating the proxies. The notifications may
+  // clone an existing request, and its state could be inconsistent.
+  mRequest->SetValidator(nullptr);
+  mRequest = nullptr;
+
+  // If an error occurred, we will want to cancel the new request, and make the
+  // validating proxies point to it. Any proxies still bound to the original
+  // request which are not validating should remain untouched.
+  if (aCancelRequest) {
+    MOZ_ASSERT(mNewRequest);
+    mNewRequest->CancelAndAbort(NS_BINDING_ABORTED);
+  }
+
+  // We have finished validating the request, so we can safely take ownership
+  // of the proxy list. imgRequestProxy::SyncNotifyListener can mutate the list
+  // if imgRequestProxy::CancelAndForgetObserver is called by its owner. Note
+  // that any potential notifications should still be suppressed in
+  // imgRequestProxy::ChangeOwner because we haven't cleared the validating
+  // flag yet, and thus they will remain deferred.
+  AutoTArray<RefPtr<imgRequestProxy>, 4> proxies(std::move(mProxies));
+
+  for (auto& proxy : proxies) {
+    // First update the state of all proxies before notifying any of them
+    // to ensure a consistent state (e.g. in case the notification causes
+    // other proxies to be touched indirectly.)
+    MOZ_ASSERT(proxy->IsValidating());
+    MOZ_ASSERT(proxy->NotificationsDeferred(),
+               "Proxies waiting on cache validation should be "
+               "deferring notifications!");
+    if (mNewRequest) {
+      proxy->ChangeOwner(mNewRequest);
+    }
+    proxy->ClearValidating();
+  }
+
+  mNewRequest = nullptr;
+  mNewEntry = nullptr;
+
+  for (auto& proxy : proxies) {
+    if (aSyncNotify) {
+      // Notify synchronously, because the caller knows we are already in an
+      // asynchronously-called function (e.g. OnStartRequest).
+      proxy->SyncNotifyListener();
+    } else {
+      // Notify asynchronously, because the caller does not know our current
+      // call state (e.g. ~imgCacheValidator).
+      proxy->NotifyListener();
+    }
+  }
+}
+
+/** nsIRequestObserver methods **/
+
+NS_IMETHODIMP
+imgCacheValidator::OnStartRequest(nsIRequest* aRequest) {
+  // We may be holding on to a document, so ensure that it's released.
+  RefPtr<Document> document = mDocument.forget();
+
+  // If for some reason we don't still have an existing request (probably
+  // because OnStartRequest got delivered more than once), just bail.
+  if (!mRequest) {
+    MOZ_ASSERT_UNREACHABLE("OnStartRequest delivered more than once?");
+    aRequest->CancelWithReason(NS_BINDING_ABORTED,
+                               "OnStartRequest delivered more than once?"_ns);
+    return NS_ERROR_FAILURE;
+  }
+
+  // If this request is coming from cache and has the same URI as our
+  // imgRequest, the request all our proxies are pointing at is valid, and all
+  // we have to do is tell them to notify their listeners.
+  nsCOMPtr<nsICacheInfoChannel> cacheChan(do_QueryInterface(aRequest));
+  nsCOMPtr<nsIChannel> channel(do_QueryInterface(aRequest));
+  if (cacheChan && channel) {
+    bool isFromCache = false;
+    cacheChan->IsFromCache(&isFromCache);
+
+    nsCOMPtr<nsIURI> channelURI;
+    channel->GetURI(getter_AddRefs(channelURI));
+
+    nsCOMPtr<nsIURI> finalURI;
+    mRequest->GetFinalURI(getter_AddRefs(finalURI));
+
+    bool sameURI = false;
+    if (channelURI && finalURI) {
+      channelURI->Equals(finalURI, &sameURI);
+    }
+
+    if (isFromCache && sameURI) {
+      // We don't need to load this any more.
+      aRequest->CancelWithReason(NS_BINDING_ABORTED,
+                                 "imgCacheValidator::OnStartRequest"_ns);
+      mNewRequest = nullptr;
+
+      // Clear the validator before updating the proxies. The notifications may
+      // clone an existing request, and its state could be inconsistent.
+      mRequest->SetLoadId(document);
+      mRequest->SetInnerWindowID(mInnerWindowId);
+      UpdateProxies(/* aCancelRequest */ false, /* aSyncNotify */ true);
+      return NS_OK;
+    }
+  }
+
+  // We can't load out of cache. We have to create a whole new request for the
+  // data that's coming in off the channel.
+  nsCOMPtr<nsIURI> uri;
+  mRequest->GetURI(getter_AddRefs(uri));
+
+  LOG_MSG_WITH_PARAM(gImgLog,
+                     "imgCacheValidator::OnStartRequest creating new request",
+                     "uri", uri);
+
+  CORSMode corsmode = mRequest->GetCORSMode();
+  nsCOMPtr<nsIReferrerInfo> referrerInfo = mRequest->GetReferrerInfo();
+  nsCOMPtr<nsIPrincipal> triggeringPrincipal =
+      mRequest->GetTriggeringPrincipal();
+
+  // Doom the old request's cache entry
+  mRequest->RemoveFromCache();
+
+  // We use originalURI here to fulfil the imgIRequest contract on GetURI.
+  nsCOMPtr<nsIURI> originalURI;
+  channel->GetOriginalURI(getter_AddRefs(originalURI));
+  nsresult rv = mNewRequest->Init(originalURI, uri, mHadInsecureRedirect,
+                                  aRequest, channel, mNewEntry, document,
+                                  triggeringPrincipal, corsmode, referrerInfo);
+  if (NS_FAILED(rv)) {
+    UpdateProxies(/* aCancelRequest */ true, /* aSyncNotify */ true);
+    return rv;
+  }
+
+  mDestListener = new ProxyListener(mNewRequest);
+
+  // Try to add the new request into the cache. Note that the entry must be in
+  // the cache before the proxies' ownership changes, because adding a proxy
+  // changes the caching behaviour for imgRequests.
+  mImgLoader->PutIntoCache(mNewRequest->CacheKey(), mNewEntry);
+  UpdateProxies(/* aCancelRequest */ false, /* aSyncNotify */ true);
+  return mDestListener->OnStartRequest(aRequest);
+}
+
+NS_IMETHODIMP
+imgCacheValidator::OnStopRequest(nsIRequest* aRequest, nsresult status) {
+  // Be sure we've released the document that we may have been holding on to.
+  mDocument = nullptr;
+
+  if (!mDestListener) {
+    return NS_OK;
+  }
+
+  return mDestListener->OnStopRequest(aRequest, status);
+}
+
+/** nsIStreamListener methods **/
+
+NS_IMETHODIMP
+imgCacheValidator::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* inStr,
+                                   uint64_t sourceOffset, uint32_t count) {
+  if (!mDestListener) {
+    // XXX see bug 113959
+    uint32_t _retval;
+    inStr->ReadSegments(NS_DiscardSegment, nullptr, count, &_retval);
+    return NS_OK;
+  }
+
+  return mDestListener->OnDataAvailable(aRequest, inStr, sourceOffset, count);
+}
+
+/** nsIThreadRetargetableStreamListener methods **/
+
+NS_IMETHODIMP
+imgCacheValidator::CheckListenerChain() {
+  NS_ASSERTION(NS_IsMainThread(), "Should be on the main thread!");
+  nsresult rv = NS_OK;
+  nsCOMPtr<nsIThreadRetargetableStreamListener> retargetableListener =
+      do_QueryInterface(mDestListener, &rv);
+  if (retargetableListener) {
+    rv = retargetableListener->CheckListenerChain();
+  }
+  MOZ_LOG(
+      gImgLog, LogLevel::Debug,
+      ("[this=%p] imgCacheValidator::CheckListenerChain -- rv %" PRId32 "=%s",
+       this, static_cast<uint32_t>(rv),
+       NS_SUCCEEDED(rv) ? "succeeded" : "failed"));
+  return rv;
+}
+
+/** nsIInterfaceRequestor methods **/
+
+NS_IMETHODIMP
+imgCacheValidator::GetInterface(const nsIID& aIID, void** aResult) {
+  if (aIID.Equals(NS_GET_IID(nsIChannelEventSink))) {
+    return QueryInterface(aIID, aResult);
+  }
+
+  return mProgressProxy->GetInterface(aIID, aResult);
+}
+
+// These functions are materially the same as the same functions in imgRequest.
+// We duplicate them because we're verifying whether cache loads are necessary,
+// not unconditionally loading.
+
+/** nsIChannelEventSink methods **/
+NS_IMETHODIMP
+imgCacheValidator::AsyncOnChannelRedirect(
+    nsIChannel* oldChannel, nsIChannel* newChannel, uint32_t flags,
+    nsIAsyncVerifyRedirectCallback* callback) {
+  // Note all cache information we get from the old channel.
+  mNewRequest->SetCacheValidation(mNewEntry, oldChannel);
+
+  // If the previous URI is a non-HTTPS URI, record that fact for later use by
+  // security code, which needs to know whether there is an insecure load at any
+  // point in the redirect chain.
+  nsCOMPtr<nsIURI> oldURI;
+  bool schemeLocal = false;
+  if (NS_FAILED(oldChannel->GetURI(getter_AddRefs(oldURI))) ||
+      NS_FAILED(NS_URIChainHasFlags(
+          oldURI, nsIProtocolHandler::URI_IS_LOCAL_RESOURCE, &schemeLocal)) ||
+      (!oldURI->SchemeIs("https") && !oldURI->SchemeIs("chrome") &&
+       !schemeLocal)) {
+    mHadInsecureRedirect = true;
+  }
+
+  // Prepare for callback
+  mRedirectCallback = callback;
+  mRedirectChannel = newChannel;
+
+  return mProgressProxy->AsyncOnChannelRedirect(oldChannel, newChannel, flags,
+                                                this);
+}
+
+NS_IMETHODIMP
+imgCacheValidator::OnRedirectVerifyCallback(nsresult aResult) {
+  // If we've already been told to abort, just do so.
+  if (NS_FAILED(aResult)) {
+    mRedirectCallback->OnRedirectVerifyCallback(aResult);
+    mRedirectCallback = nullptr;
+    mRedirectChannel = nullptr;
+    return NS_OK;
+  }
+
+  // make sure we have a protocol that returns data rather than opens
+  // an external application, e.g. mailto:
+  nsCOMPtr<nsIURI> uri;
+  mRedirectChannel->GetURI(getter_AddRefs(uri));
+
+  nsresult result = NS_OK;
+
+  if (nsContentUtils::IsExternalProtocol(uri)) {
+    result = NS_ERROR_ABORT;
+  }
+
+  mRedirectCallback->OnRedirectVerifyCallback(result);
+  mRedirectCallback = nullptr;
+  mRedirectChannel = nullptr;
+  return NS_OK;
+}