Add m-esr52 at 52.6.0

1 files changed, 887 insertions, 0 deletions

diff --git a/image/FrameAnimator.cpp b/image/FrameAnimator.cpp
new file mode 100644
index 000000000..8c29b5636
--- /dev/null
+++ b/image/FrameAnimator.cpp
@@ -0,0 +1,887 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FrameAnimator.h"
+
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Move.h"
+#include "imgIContainer.h"
+#include "LookupResult.h"
+#include "MainThreadUtils.h"
+#include "RasterImage.h"
+
+#include "pixman.h"
+
+namespace mozilla {
+
+using namespace gfx;
+
+namespace image {
+
+///////////////////////////////////////////////////////////////////////////////
+// AnimationState implementation.
+///////////////////////////////////////////////////////////////////////////////
+
+void
+AnimationState::SetDoneDecoding(bool aDone)
+{
+  mDoneDecoding = aDone;
+}
+
+void
+AnimationState::ResetAnimation()
+{
+  mCurrentAnimationFrameIndex = 0;
+}
+
+void
+AnimationState::SetAnimationMode(uint16_t aAnimationMode)
+{
+  mAnimationMode = aAnimationMode;
+}
+
+void
+AnimationState::UpdateKnownFrameCount(uint32_t aFrameCount)
+{
+  if (aFrameCount <= mFrameCount) {
+    // Nothing to do. Since we can redecode animated images, we may see the same
+    // sequence of updates replayed again, so seeing a smaller frame count than
+    // what we already know about doesn't indicate an error.
+    return;
+  }
+
+  MOZ_ASSERT(!mDoneDecoding, "Adding new frames after decoding is finished?");
+  MOZ_ASSERT(aFrameCount <= mFrameCount + 1, "Skipped a frame?");
+
+  mFrameCount = aFrameCount;
+}
+
+Maybe<uint32_t>
+AnimationState::FrameCount() const
+{
+  return mDoneDecoding ? Some(mFrameCount) : Nothing();
+}
+
+void
+AnimationState::SetFirstFrameRefreshArea(const IntRect& aRefreshArea)
+{
+  mFirstFrameRefreshArea = aRefreshArea;
+}
+
+void
+AnimationState::InitAnimationFrameTimeIfNecessary()
+{
+  if (mCurrentAnimationFrameTime.IsNull()) {
+    mCurrentAnimationFrameTime = TimeStamp::Now();
+  }
+}
+
+void
+AnimationState::SetAnimationFrameTime(const TimeStamp& aTime)
+{
+  mCurrentAnimationFrameTime = aTime;
+}
+
+uint32_t
+AnimationState::GetCurrentAnimationFrameIndex() const
+{
+  return mCurrentAnimationFrameIndex;
+}
+
+FrameTimeout
+AnimationState::LoopLength() const
+{
+  // If we don't know the loop length yet, we have to treat it as infinite.
+  if (!mLoopLength) {
+    return FrameTimeout::Forever();
+  }
+
+  MOZ_ASSERT(mDoneDecoding, "We know the loop length but decoding isn't done?");
+
+  // If we're not looping, a single loop time has no meaning.
+  if (mAnimationMode != imgIContainer::kNormalAnimMode) {
+    return FrameTimeout::Forever();
+  }
+
+  return *mLoopLength;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////
+// FrameAnimator implementation.
+///////////////////////////////////////////////////////////////////////////////
+
+TimeStamp
+FrameAnimator::GetCurrentImgFrameEndTime(AnimationState& aState) const
+{
+  TimeStamp currentFrameTime = aState.mCurrentAnimationFrameTime;
+  FrameTimeout timeout = GetTimeoutForFrame(aState.mCurrentAnimationFrameIndex);
+
+  if (timeout == FrameTimeout::Forever()) {
+    // We need to return a sentinel value in this case, because our logic
+    // doesn't work correctly if we have an infinitely long timeout. We use one
+    // year in the future as the sentinel because it works with the loop in
+    // RequestRefresh() below.
+    // XXX(seth): It'd be preferable to make our logic work correctly with
+    // infinitely long timeouts.
+    return TimeStamp::NowLoRes() +
+           TimeDuration::FromMilliseconds(31536000.0);
+  }
+
+  TimeDuration durationOfTimeout =
+    TimeDuration::FromMilliseconds(double(timeout.AsMilliseconds()));
+  TimeStamp currentFrameEndTime = currentFrameTime + durationOfTimeout;
+
+  return currentFrameEndTime;
+}
+
+RefreshResult
+FrameAnimator::AdvanceFrame(AnimationState& aState, TimeStamp aTime)
+{
+  NS_ASSERTION(aTime <= TimeStamp::Now(),
+               "Given time appears to be in the future");
+  PROFILER_LABEL_FUNC(js::ProfileEntry::Category::GRAPHICS);
+
+  RefreshResult ret;
+
+  // Determine what the next frame is, taking into account looping.
+  uint32_t currentFrameIndex = aState.mCurrentAnimationFrameIndex;
+  uint32_t nextFrameIndex = currentFrameIndex + 1;
+
+  // Check if we're at the end of the loop. (FrameCount() returns Nothing() if
+  // we don't know the total count yet.)
+  if (aState.FrameCount() == Some(nextFrameIndex)) {
+    // If we are not looping forever, initialize the loop counter
+    if (aState.mLoopRemainingCount < 0 && aState.LoopCount() >= 0) {
+      aState.mLoopRemainingCount = aState.LoopCount();
+    }
+
+    // If animation mode is "loop once", or we're at end of loop counter,
+    // it's time to stop animating.
+    if (aState.mAnimationMode == imgIContainer::kLoopOnceAnimMode ||
+        aState.mLoopRemainingCount == 0) {
+      ret.mAnimationFinished = true;
+    }
+
+    nextFrameIndex = 0;
+
+    if (aState.mLoopRemainingCount > 0) {
+      aState.mLoopRemainingCount--;
+    }
+
+    // If we're done, exit early.
+    if (ret.mAnimationFinished) {
+      return ret;
+    }
+  }
+
+  if (nextFrameIndex >= aState.KnownFrameCount()) {
+    // We've already advanced to the last decoded frame, nothing more we can do.
+    // We're blocked by network/decoding from displaying the animation at the
+    // rate specified, so that means the frame we are displaying (the latest
+    // available) is the frame we want to be displaying at this time. So we
+    // update the current animation time. If we didn't update the current
+    // animation time then it could lag behind, which would indicate that we are
+    // behind in the animation and should try to catch up. When we are done
+    // decoding (and thus can loop around back to the start of the animation) we
+    // would then jump to a random point in the animation to try to catch up.
+    // But we were never behind in the animation.
+    aState.mCurrentAnimationFrameTime = aTime;
+    return ret;
+  }
+
+  // There can be frames in the surface cache with index >= KnownFrameCount()
+  // which GetRawFrame() can access because an async decoder has decoded them,
+  // but which AnimationState doesn't know about yet because we haven't received
+  // the appropriate notification on the main thread. Make sure we stay in sync
+  // with AnimationState.
+  MOZ_ASSERT(nextFrameIndex < aState.KnownFrameCount());
+  RawAccessFrameRef nextFrame = GetRawFrame(nextFrameIndex);
+
+  // We should always check to see if we have the next frame even if we have
+  // previously finished decoding. If we needed to redecode (e.g. due to a draw
+  // failure) we would have discarded all the old frames and may not yet have
+  // the new ones.
+  if (!nextFrame || !nextFrame->IsFinished()) {
+    // Uh oh, the frame we want to show is currently being decoded (partial)
+    // Wait until the next refresh driver tick and try again
+    return ret;
+  }
+
+  if (GetTimeoutForFrame(nextFrameIndex) == FrameTimeout::Forever()) {
+    ret.mAnimationFinished = true;
+  }
+
+  if (nextFrameIndex == 0) {
+    ret.mDirtyRect = aState.FirstFrameRefreshArea();
+  } else {
+    MOZ_ASSERT(nextFrameIndex == currentFrameIndex + 1);
+
+    // Change frame
+    if (!DoBlend(&ret.mDirtyRect, currentFrameIndex, nextFrameIndex)) {
+      // something went wrong, move on to next
+      NS_WARNING("FrameAnimator::AdvanceFrame(): Compositing of frame failed");
+      nextFrame->SetCompositingFailed(true);
+      aState.mCurrentAnimationFrameTime = GetCurrentImgFrameEndTime(aState);
+      aState.mCurrentAnimationFrameIndex = nextFrameIndex;
+
+      return ret;
+    }
+
+    nextFrame->SetCompositingFailed(false);
+  }
+
+  aState.mCurrentAnimationFrameTime = GetCurrentImgFrameEndTime(aState);
+
+  // If we can get closer to the current time by a multiple of the image's loop
+  // time, we should. We can only do this if we're done decoding; otherwise, we
+  // don't know the full loop length, and LoopLength() will have to return
+  // FrameTimeout::Forever().
+  FrameTimeout loopTime = aState.LoopLength();
+  if (loopTime != FrameTimeout::Forever()) {
+    TimeDuration delay = aTime - aState.mCurrentAnimationFrameTime;
+    if (delay.ToMilliseconds() > loopTime.AsMilliseconds()) {
+      // Explicitly use integer division to get the floor of the number of
+      // loops.
+      uint64_t loops = static_cast<uint64_t>(delay.ToMilliseconds())
+                     / loopTime.AsMilliseconds();
+      aState.mCurrentAnimationFrameTime +=
+        TimeDuration::FromMilliseconds(loops * loopTime.AsMilliseconds());
+    }
+  }
+
+  // Set currentAnimationFrameIndex at the last possible moment
+  aState.mCurrentAnimationFrameIndex = nextFrameIndex;
+
+  // If we're here, we successfully advanced the frame.
+  ret.mFrameAdvanced = true;
+
+  return ret;
+}
+
+RefreshResult
+FrameAnimator::RequestRefresh(AnimationState& aState, const TimeStamp& aTime)
+{
+  // only advance the frame if the current time is greater than or
+  // equal to the current frame's end time.
+  TimeStamp currentFrameEndTime = GetCurrentImgFrameEndTime(aState);
+
+  // By default, an empty RefreshResult.
+  RefreshResult ret;
+
+  while (currentFrameEndTime <= aTime) {
+    TimeStamp oldFrameEndTime = currentFrameEndTime;
+
+    RefreshResult frameRes = AdvanceFrame(aState, aTime);
+
+    // Accumulate our result for returning to callers.
+    ret.Accumulate(frameRes);
+
+    currentFrameEndTime = GetCurrentImgFrameEndTime(aState);
+
+    // If we didn't advance a frame, and our frame end time didn't change,
+    // then we need to break out of this loop & wait for the frame(s)
+    // to finish downloading.
+    if (!frameRes.mFrameAdvanced && (currentFrameEndTime == oldFrameEndTime)) {
+      break;
+    }
+  }
+
+  return ret;
+}
+
+LookupResult
+FrameAnimator::GetCompositedFrame(uint32_t aFrameNum)
+{
+  // If we have a composited version of this frame, return that.
+  if (mLastCompositedFrameIndex == int32_t(aFrameNum)) {
+    return LookupResult(DrawableSurface(mCompositingFrame->DrawableRef()),
+                        MatchType::EXACT);
+  }
+
+  // Otherwise return the raw frame. DoBlend is required to ensure that we only
+  // hit this case if the frame is not paletted and doesn't require compositing.
+  LookupResult result =
+    SurfaceCache::Lookup(ImageKey(mImage),
+                         RasterSurfaceKey(mSize,
+                                          DefaultSurfaceFlags(),
+                                          PlaybackType::eAnimated));
+  if (!result) {
+    return result;
+  }
+
+  // Seek to the appropriate frame. If seeking fails, it means that we couldn't
+  // get the frame we're looking for; treat this as if the lookup failed.
+  if (NS_FAILED(result.Surface().Seek(aFrameNum))) {
+    return LookupResult(MatchType::NOT_FOUND);
+  }
+
+  MOZ_ASSERT(!result.Surface()->GetIsPaletted(),
+             "About to return a paletted frame");
+
+  return result;
+}
+
+FrameTimeout
+FrameAnimator::GetTimeoutForFrame(uint32_t aFrameNum) const
+{
+  RawAccessFrameRef frame = GetRawFrame(aFrameNum);
+  if (frame) {
+    AnimationData data = frame->GetAnimationData();
+    return data.mTimeout;
+  }
+
+  NS_WARNING("No frame; called GetTimeoutForFrame too early?");
+  return FrameTimeout::FromRawMilliseconds(100);
+}
+
+static void
+DoCollectSizeOfCompositingSurfaces(const RawAccessFrameRef& aSurface,
+                                   SurfaceMemoryCounterType aType,
+                                   nsTArray<SurfaceMemoryCounter>& aCounters,
+                                   MallocSizeOf aMallocSizeOf)
+{
+  // Concoct a SurfaceKey for this surface.
+  SurfaceKey key = RasterSurfaceKey(aSurface->GetImageSize(),
+                                    DefaultSurfaceFlags(),
+                                    PlaybackType::eStatic);
+
+  // Create a counter for this surface.
+  SurfaceMemoryCounter counter(key, /* aIsLocked = */ true, aType);
+
+  // Extract the surface's memory usage information.
+  size_t heap = 0, nonHeap = 0;
+  aSurface->AddSizeOfExcludingThis(aMallocSizeOf, heap, nonHeap);
+  counter.Values().SetDecodedHeap(heap);
+  counter.Values().SetDecodedNonHeap(nonHeap);
+
+  // Record it.
+  aCounters.AppendElement(counter);
+}
+
+void
+FrameAnimator::CollectSizeOfCompositingSurfaces(
+    nsTArray<SurfaceMemoryCounter>& aCounters,
+    MallocSizeOf aMallocSizeOf) const
+{
+  if (mCompositingFrame) {
+    DoCollectSizeOfCompositingSurfaces(mCompositingFrame,
+                                       SurfaceMemoryCounterType::COMPOSITING,
+                                       aCounters,
+                                       aMallocSizeOf);
+  }
+
+  if (mCompositingPrevFrame) {
+    DoCollectSizeOfCompositingSurfaces(mCompositingPrevFrame,
+                                       SurfaceMemoryCounterType::COMPOSITING_PREV,
+                                       aCounters,
+                                       aMallocSizeOf);
+  }
+}
+
+RawAccessFrameRef
+FrameAnimator::GetRawFrame(uint32_t aFrameNum) const
+{
+  LookupResult result =
+    SurfaceCache::Lookup(ImageKey(mImage),
+                         RasterSurfaceKey(mSize,
+                                          DefaultSurfaceFlags(),
+                                          PlaybackType::eAnimated));
+  if (!result) {
+    return RawAccessFrameRef();
+  }
+
+  // Seek to the frame we want. If seeking fails, it means we couldn't get the
+  // frame we're looking for, so we bail here to avoid returning the wrong frame
+  // to the caller.
+  if (NS_FAILED(result.Surface().Seek(aFrameNum))) {
+    return RawAccessFrameRef();  // Not available yet.
+  }
+
+  return result.Surface()->RawAccessRef();
+}
+
+//******************************************************************************
+// DoBlend gets called when the timer for animation get fired and we have to
+// update the composited frame of the animation.
+bool
+FrameAnimator::DoBlend(IntRect* aDirtyRect,
+                       uint32_t aPrevFrameIndex,
+                       uint32_t aNextFrameIndex)
+{
+  RawAccessFrameRef prevFrame = GetRawFrame(aPrevFrameIndex);
+  RawAccessFrameRef nextFrame = GetRawFrame(aNextFrameIndex);
+
+  MOZ_ASSERT(prevFrame && nextFrame, "Should have frames here");
+
+  AnimationData prevFrameData = prevFrame->GetAnimationData();
+  if (prevFrameData.mDisposalMethod == DisposalMethod::RESTORE_PREVIOUS &&
+      !mCompositingPrevFrame) {
+    prevFrameData.mDisposalMethod = DisposalMethod::CLEAR;
+  }
+
+  IntRect prevRect = prevFrameData.mBlendRect
+                   ? prevFrameData.mRect.Intersect(*prevFrameData.mBlendRect)
+                   : prevFrameData.mRect;
+
+  bool isFullPrevFrame = prevRect.x == 0 && prevRect.y == 0 &&
+                         prevRect.width == mSize.width &&
+                         prevRect.height == mSize.height;
+
+  // Optimization: DisposeClearAll if the previous frame is the same size as
+  //               container and it's clearing itself
+  if (isFullPrevFrame &&
+      (prevFrameData.mDisposalMethod == DisposalMethod::CLEAR)) {
+    prevFrameData.mDisposalMethod = DisposalMethod::CLEAR_ALL;
+  }
+
+  AnimationData nextFrameData = nextFrame->GetAnimationData();
+
+  IntRect nextRect = nextFrameData.mBlendRect
+                   ? nextFrameData.mRect.Intersect(*nextFrameData.mBlendRect)
+                   : nextFrameData.mRect;
+
+  bool isFullNextFrame = nextRect.x == 0 && nextRect.y == 0 &&
+                         nextRect.width == mSize.width &&
+                         nextRect.height == mSize.height;
+
+  if (!nextFrame->GetIsPaletted()) {
+    // Optimization: Skip compositing if the previous frame wants to clear the
+    //               whole image
+    if (prevFrameData.mDisposalMethod == DisposalMethod::CLEAR_ALL) {
+      aDirtyRect->SetRect(0, 0, mSize.width, mSize.height);
+      return true;
+    }
+
+    // Optimization: Skip compositing if this frame is the same size as the
+    //               container and it's fully drawing over prev frame (no alpha)
+    if (isFullNextFrame &&
+        (nextFrameData.mDisposalMethod != DisposalMethod::RESTORE_PREVIOUS) &&
+        !nextFrameData.mHasAlpha) {
+      aDirtyRect->SetRect(0, 0, mSize.width, mSize.height);
+      return true;
+    }
+  }
+
+  // Calculate area that needs updating
+  switch (prevFrameData.mDisposalMethod) {
+    default:
+      MOZ_FALLTHROUGH_ASSERT("Unexpected DisposalMethod");
+    case DisposalMethod::NOT_SPECIFIED:
+    case DisposalMethod::KEEP:
+      *aDirtyRect = nextRect;
+      break;
+
+    case DisposalMethod::CLEAR_ALL:
+      // Whole image container is cleared
+      aDirtyRect->SetRect(0, 0, mSize.width, mSize.height);
+      break;
+
+    case DisposalMethod::CLEAR:
+      // Calc area that needs to be redrawn (the combination of previous and
+      // this frame)
+      // XXX - This could be done with multiple framechanged calls
+      //       Having prevFrame way at the top of the image, and nextFrame
+      //       way at the bottom, and both frames being small, we'd be
+      //       telling framechanged to refresh the whole image when only two
+      //       small areas are needed.
+      aDirtyRect->UnionRect(nextRect, prevRect);
+      break;
+
+    case DisposalMethod::RESTORE_PREVIOUS:
+      aDirtyRect->SetRect(0, 0, mSize.width, mSize.height);
+      break;
+  }
+
+  // Optimization:
+  //   Skip compositing if the last composited frame is this frame
+  //   (Only one composited frame was made for this animation.  Example:
+  //    Only Frame 3 of a 10 frame image required us to build a composite frame
+  //    On the second loop, we do not need to rebuild the frame
+  //    since it's still sitting in compositingFrame)
+  if (mLastCompositedFrameIndex == int32_t(aNextFrameIndex)) {
+    return true;
+  }
+
+  bool needToBlankComposite = false;
+
+  // Create the Compositing Frame
+  if (!mCompositingFrame) {
+    RefPtr<imgFrame> newFrame = new imgFrame;
+    nsresult rv = newFrame->InitForDecoder(mSize,
+                                           SurfaceFormat::B8G8R8A8);
+    if (NS_FAILED(rv)) {
+      mCompositingFrame.reset();
+      return false;
+    }
+    mCompositingFrame = newFrame->RawAccessRef();
+    needToBlankComposite = true;
+  } else if (int32_t(aNextFrameIndex) != mLastCompositedFrameIndex+1) {
+
+    // If we are not drawing on top of last composited frame,
+    // then we are building a new composite frame, so let's clear it first.
+    needToBlankComposite = true;
+  }
+
+  AnimationData compositingFrameData = mCompositingFrame->GetAnimationData();
+
+  // More optimizations possible when next frame is not transparent
+  // But if the next frame has DisposalMethod::RESTORE_PREVIOUS,
+  // this "no disposal" optimization is not possible,
+  // because the frame in "after disposal operation" state
+  // needs to be stored in compositingFrame, so it can be
+  // copied into compositingPrevFrame later.
+  bool doDisposal = true;
+  if (!nextFrameData.mHasAlpha &&
+      nextFrameData.mDisposalMethod != DisposalMethod::RESTORE_PREVIOUS) {
+    if (isFullNextFrame) {
+      // Optimization: No need to dispose prev.frame when
+      // next frame is full frame and not transparent.
+      doDisposal = false;
+      // No need to blank the composite frame
+      needToBlankComposite = false;
+    } else {
+      if ((prevRect.x >= nextRect.x) && (prevRect.y >= nextRect.y) &&
+          (prevRect.x + prevRect.width <= nextRect.x + nextRect.width) &&
+          (prevRect.y + prevRect.height <= nextRect.y + nextRect.height)) {
+        // Optimization: No need to dispose prev.frame when
+        // next frame fully overlaps previous frame.
+        doDisposal = false;
+      }
+    }
+  }
+
+  if (doDisposal) {
+    // Dispose of previous: clear, restore, or keep (copy)
+    switch (prevFrameData.mDisposalMethod) {
+      case DisposalMethod::CLEAR:
+        if (needToBlankComposite) {
+          // If we just created the composite, it could have anything in its
+          // buffer. Clear whole frame
+          ClearFrame(compositingFrameData.mRawData,
+                     compositingFrameData.mRect);
+        } else {
+          // Only blank out previous frame area (both color & Mask/Alpha)
+          ClearFrame(compositingFrameData.mRawData,
+                     compositingFrameData.mRect,
+                     prevRect);
+        }
+        break;
+
+      case DisposalMethod::CLEAR_ALL:
+        ClearFrame(compositingFrameData.mRawData,
+                   compositingFrameData.mRect);
+        break;
+
+      case DisposalMethod::RESTORE_PREVIOUS:
+        // It would be better to copy only the area changed back to
+        // compositingFrame.
+        if (mCompositingPrevFrame) {
+          AnimationData compositingPrevFrameData =
+            mCompositingPrevFrame->GetAnimationData();
+
+          CopyFrameImage(compositingPrevFrameData.mRawData,
+                         compositingPrevFrameData.mRect,
+                         compositingFrameData.mRawData,
+                         compositingFrameData.mRect);
+
+          // destroy only if we don't need it for this frame's disposal
+          if (nextFrameData.mDisposalMethod !=
+              DisposalMethod::RESTORE_PREVIOUS) {
+            mCompositingPrevFrame.reset();
+          }
+        } else {
+          ClearFrame(compositingFrameData.mRawData,
+                     compositingFrameData.mRect);
+        }
+        break;
+
+      default:
+        MOZ_FALLTHROUGH_ASSERT("Unexpected DisposalMethod");
+      case DisposalMethod::NOT_SPECIFIED:
+      case DisposalMethod::KEEP:
+        // Copy previous frame into compositingFrame before we put the new
+        // frame on top
+        // Assumes that the previous frame represents a full frame (it could be
+        // smaller in size than the container, as long as the frame before it
+        // erased itself)
+        // Note: Frame 1 never gets into DoBlend(), so (aNextFrameIndex - 1)
+        // will always be a valid frame number.
+        if (mLastCompositedFrameIndex != int32_t(aNextFrameIndex - 1)) {
+          if (isFullPrevFrame && !prevFrame->GetIsPaletted()) {
+            // Just copy the bits
+            CopyFrameImage(prevFrameData.mRawData,
+                           prevRect,
+                           compositingFrameData.mRawData,
+                           compositingFrameData.mRect);
+          } else {
+            if (needToBlankComposite) {
+              // Only blank composite when prev is transparent or not full.
+              if (prevFrameData.mHasAlpha || !isFullPrevFrame) {
+                ClearFrame(compositingFrameData.mRawData,
+                           compositingFrameData.mRect);
+              }
+            }
+            DrawFrameTo(prevFrameData.mRawData, prevFrameData.mRect,
+                        prevFrameData.mPaletteDataLength,
+                        prevFrameData.mHasAlpha,
+                        compositingFrameData.mRawData,
+                        compositingFrameData.mRect,
+                        prevFrameData.mBlendMethod,
+                        prevFrameData.mBlendRect);
+          }
+        }
+    }
+  } else if (needToBlankComposite) {
+    // If we just created the composite, it could have anything in its
+    // buffers. Clear them
+    ClearFrame(compositingFrameData.mRawData,
+               compositingFrameData.mRect);
+  }
+
+  // Check if the frame we are composing wants the previous image restored after
+  // it is done. Don't store it (again) if last frame wanted its image restored
+  // too
+  if ((nextFrameData.mDisposalMethod == DisposalMethod::RESTORE_PREVIOUS) &&
+      (prevFrameData.mDisposalMethod != DisposalMethod::RESTORE_PREVIOUS)) {
+    // We are storing the whole image.
+    // It would be better if we just stored the area that nextFrame is going to
+    // overwrite.
+    if (!mCompositingPrevFrame) {
+      RefPtr<imgFrame> newFrame = new imgFrame;
+      nsresult rv = newFrame->InitForDecoder(mSize,
+                                             SurfaceFormat::B8G8R8A8);
+      if (NS_FAILED(rv)) {
+        mCompositingPrevFrame.reset();
+        return false;
+      }
+
+      mCompositingPrevFrame = newFrame->RawAccessRef();
+    }
+
+    AnimationData compositingPrevFrameData =
+      mCompositingPrevFrame->GetAnimationData();
+
+    CopyFrameImage(compositingFrameData.mRawData,
+                   compositingFrameData.mRect,
+                   compositingPrevFrameData.mRawData,
+                   compositingPrevFrameData.mRect);
+
+    mCompositingPrevFrame->Finish();
+  }
+
+  // blit next frame into it's correct spot
+  DrawFrameTo(nextFrameData.mRawData, nextFrameData.mRect,
+              nextFrameData.mPaletteDataLength,
+              nextFrameData.mHasAlpha,
+              compositingFrameData.mRawData,
+              compositingFrameData.mRect,
+              nextFrameData.mBlendMethod,
+              nextFrameData.mBlendRect);
+
+  // Tell the image that it is fully 'downloaded'.
+  mCompositingFrame->Finish();
+
+  mLastCompositedFrameIndex = int32_t(aNextFrameIndex);
+
+  return true;
+}
+
+//******************************************************************************
+// Fill aFrame with black. Does also clears the mask.
+void
+FrameAnimator::ClearFrame(uint8_t* aFrameData, const IntRect& aFrameRect)
+{
+  if (!aFrameData) {
+    return;
+  }
+
+  memset(aFrameData, 0, aFrameRect.width * aFrameRect.height * 4);
+}
+
+//******************************************************************************
+void
+FrameAnimator::ClearFrame(uint8_t* aFrameData, const IntRect& aFrameRect,
+                          const IntRect& aRectToClear)
+{
+  if (!aFrameData || aFrameRect.width <= 0 || aFrameRect.height <= 0 ||
+      aRectToClear.width <= 0 || aRectToClear.height <= 0) {
+    return;
+  }
+
+  IntRect toClear = aFrameRect.Intersect(aRectToClear);
+  if (toClear.IsEmpty()) {
+    return;
+  }
+
+  uint32_t bytesPerRow = aFrameRect.width * 4;
+  for (int row = toClear.y; row < toClear.y + toClear.height; ++row) {
+    memset(aFrameData + toClear.x * 4 + row * bytesPerRow, 0,
+           toClear.width * 4);
+  }
+}
+
+//******************************************************************************
+// Whether we succeed or fail will not cause a crash, and there's not much
+// we can do about a failure, so there we don't return a nsresult
+bool
+FrameAnimator::CopyFrameImage(const uint8_t* aDataSrc,
+                              const IntRect& aRectSrc,
+                              uint8_t* aDataDest,
+                              const IntRect& aRectDest)
+{
+  uint32_t dataLengthSrc = aRectSrc.width * aRectSrc.height * 4;
+  uint32_t dataLengthDest = aRectDest.width * aRectDest.height * 4;
+
+  if (!aDataDest || !aDataSrc || dataLengthSrc != dataLengthDest) {
+    return false;
+  }
+
+  memcpy(aDataDest, aDataSrc, dataLengthDest);
+
+  return true;
+}
+
+nsresult
+FrameAnimator::DrawFrameTo(const uint8_t* aSrcData, const IntRect& aSrcRect,
+                           uint32_t aSrcPaletteLength, bool aSrcHasAlpha,
+                           uint8_t* aDstPixels, const IntRect& aDstRect,
+                           BlendMethod aBlendMethod, const Maybe<IntRect>& aBlendRect)
+{
+  NS_ENSURE_ARG_POINTER(aSrcData);
+  NS_ENSURE_ARG_POINTER(aDstPixels);
+
+  // According to both AGIF and APNG specs, offsets are unsigned
+  if (aSrcRect.x < 0 || aSrcRect.y < 0) {
+    NS_WARNING("FrameAnimator::DrawFrameTo: negative offsets not allowed");
+    return NS_ERROR_FAILURE;
+  }
+  // Outside the destination frame, skip it
+  if ((aSrcRect.x > aDstRect.width) || (aSrcRect.y > aDstRect.height)) {
+    return NS_OK;
+  }
+
+  if (aSrcPaletteLength) {
+    // Larger than the destination frame, clip it
+    int32_t width = std::min(aSrcRect.width, aDstRect.width - aSrcRect.x);
+    int32_t height = std::min(aSrcRect.height, aDstRect.height - aSrcRect.y);
+
+    // The clipped image must now fully fit within destination image frame
+    NS_ASSERTION((aSrcRect.x >= 0) && (aSrcRect.y >= 0) &&
+                 (aSrcRect.x + width <= aDstRect.width) &&
+                 (aSrcRect.y + height <= aDstRect.height),
+                "FrameAnimator::DrawFrameTo: Invalid aSrcRect");
+
+    // clipped image size may be smaller than source, but not larger
+    NS_ASSERTION((width <= aSrcRect.width) && (height <= aSrcRect.height),
+      "FrameAnimator::DrawFrameTo: source must be smaller than dest");
+
+    // Get pointers to image data
+    const uint8_t* srcPixels = aSrcData + aSrcPaletteLength;
+    uint32_t* dstPixels = reinterpret_cast<uint32_t*>(aDstPixels);
+    const uint32_t* colormap = reinterpret_cast<const uint32_t*>(aSrcData);
+
+    // Skip to the right offset
+    dstPixels += aSrcRect.x + (aSrcRect.y * aDstRect.width);
+    if (!aSrcHasAlpha) {
+      for (int32_t r = height; r > 0; --r) {
+        for (int32_t c = 0; c < width; c++) {
+          dstPixels[c] = colormap[srcPixels[c]];
+        }
+        // Go to the next row in the source resp. destination image
+        srcPixels += aSrcRect.width;
+        dstPixels += aDstRect.width;
+      }
+    } else {
+      for (int32_t r = height; r > 0; --r) {
+        for (int32_t c = 0; c < width; c++) {
+          const uint32_t color = colormap[srcPixels[c]];
+          if (color) {
+            dstPixels[c] = color;
+          }
+        }
+        // Go to the next row in the source resp. destination image
+        srcPixels += aSrcRect.width;
+        dstPixels += aDstRect.width;
+      }
+    }
+  } else {
+    pixman_image_t* src =
+      pixman_image_create_bits(
+          aSrcHasAlpha ? PIXMAN_a8r8g8b8 : PIXMAN_x8r8g8b8,
+          aSrcRect.width, aSrcRect.height,
+          reinterpret_cast<uint32_t*>(const_cast<uint8_t*>(aSrcData)),
+          aSrcRect.width * 4);
+    if (!src) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    pixman_image_t* dst =
+      pixman_image_create_bits(PIXMAN_a8r8g8b8,
+                               aDstRect.width,
+                               aDstRect.height,
+                               reinterpret_cast<uint32_t*>(aDstPixels),
+                               aDstRect.width * 4);
+    if (!dst) {
+      pixman_image_unref(src);
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    // XXX(seth): This is inefficient but we'll remove it quite soon when we
+    // move frame compositing into SurfacePipe. For now we need this because
+    // RemoveFrameRectFilter has transformed PNG frames with frame rects into
+    // imgFrame's with no frame rects, but with a region of 0 alpha where the
+    // frame rect should be. This works really nicely if we're using
+    // BlendMethod::OVER, but BlendMethod::SOURCE will result in that frame rect
+    // area overwriting the previous frame, which makes the animation look
+    // wrong. This quick hack fixes that by first compositing the whle new frame
+    // with BlendMethod::OVER, and then recopying the area that uses
+    // BlendMethod::SOURCE if needed. To make this work, the decoder has to
+    // provide a "blend rect" that tells us where to do this. This is just the
+    // frame rect, but hidden in a way that makes it invisible to most of the
+    // system, so we can keep eliminating dependencies on it.
+    auto op = aBlendMethod == BlendMethod::SOURCE ? PIXMAN_OP_SRC
+                                                  : PIXMAN_OP_OVER;
+
+    if (aBlendMethod == BlendMethod::OVER || !aBlendRect ||
+        (aBlendMethod == BlendMethod::SOURCE && aSrcRect.IsEqualEdges(*aBlendRect))) {
+      // We don't need to do anything clever. (Or, in the case where no blend
+      // rect was specified, we can't.)
+      pixman_image_composite32(op,
+                               src,
+                               nullptr,
+                               dst,
+                               0, 0,
+                               0, 0,
+                               aSrcRect.x, aSrcRect.y,
+                               aSrcRect.width, aSrcRect.height);
+    } else {
+      // We need to do the OVER followed by SOURCE trick above.
+      pixman_image_composite32(PIXMAN_OP_OVER,
+                               src,
+                               nullptr,
+                               dst,
+                               0, 0,
+                               0, 0,
+                               aSrcRect.x, aSrcRect.y,
+                               aSrcRect.width, aSrcRect.height);
+      pixman_image_composite32(PIXMAN_OP_SRC,
+                               src,
+                               nullptr,
+                               dst,
+                               aBlendRect->x, aBlendRect->y,
+                               0, 0,
+                               aBlendRect->x, aBlendRect->y,
+                               aBlendRect->width, aBlendRect->height);
+    }
+
+    pixman_image_unref(src);
+    pixman_image_unref(dst);
+  }
+
+  return NS_OK;
+}
+
+} // namespace image
+} // namespace mozilla