High CPU and increased memory usage fix for high-res (GIF, WEBP...) animations.

third_party/WebKit/Source/platform/graphics/BitmapImage.h

Index: third_party/WebKit/Source/platform/graphics/BitmapImage.h
diff --git a/third_party/WebKit/Source/platform/graphics/BitmapImage.h b/third_party/WebKit/Source/platform/graphics/BitmapImage.h
index 2a650a893f4364f6de016512b4c67a9031db798d..7bf2ee2afa3e7975f8e0bee048d94ee22eac7425 100644
--- a/third_party/WebKit/Source/platform/graphics/BitmapImage.h
+++ b/third_party/WebKit/Source/platform/graphics/BitmapImage.h
@@ -44,8 +44,9 @@ namespace blink {
 template <typename T> class Timer;
 
 class PLATFORM_EXPORT BitmapImage final : public Image {
-    friend class GeneratedImage;
+    friend class BitmapImageTest;
     friend class CrossfadeGeneratedImage;
+    friend class GeneratedImage;
     friend class GradientGeneratedImage;
     friend class GraphicsContext;
 public:
@@ -73,7 +74,7 @@ public:
     // This because we start and stop animating lazily. Animation starts when
     // the image is rendered, and automatically pauses once all observers no
     // longer want to render the image.
-    void stopAnimation() override;
+    void stopAnimation();
     void resetAnimation() override;
     bool maybeAnimated() override;
 
@@ -88,6 +89,11 @@ public:
     bool currentFrameIsComplete() override;
     bool currentFrameIsLazyDecoded() override;
 
+    // Called to wipe out the entire frame buffer cache and tell the image
+    // source to destroy everything; this is used when e.g. we want to free
+    // some room in the image cache.
+    void destroyDecodedData() override;
+
     ImageOrientation currentFrameOrientation();
 
     // Construct a BitmapImage with the given orientation.
@@ -96,11 +102,6 @@ public:
     void advanceAnimationForTesting() override { internalAdvanceAnimation(false); }
 
 private:
-    friend class BitmapImageTest;
-
-    void updateSize() const;
-
-private:
     enum RepetitionCountStatus {
       Unknown,    // We haven't checked the source's repetition count.
       Uncertain,  // We have a repetition count, but it might be wrong (some GIFs have a count after the image data, and will report "loop once" until all data has been decoded).
@@ -110,8 +111,11 @@ private:
     BitmapImage(const SkBitmap &, ImageObserver* = 0);
     BitmapImage(ImageObserver* = 0);
 
+    static void setAnimationCacheSizeForTesting(size_t maxCacheSize, size_t maxAnimationSizeInCache);
+
     void draw(SkCanvas*, const SkPaint&, const FloatRect& dstRect, const FloatRect& srcRect, RespectImageOrientationEnum, ImageClampingMode) override;
 
+    void updateSize() const;
     size_t currentFrame() const { return m_currentFrame; }
     size_t frameCount();
 
@@ -123,27 +127,12 @@ private:
     ImageOrientation frameOrientationAtIndex(size_t);
 
     // Decodes and caches a frame. Never accessed except internally.
-    void cacheFrame(size_t index);
-
-    // Called before accessing m_frames[index]. Returns false on index out of bounds.
-    bool ensureFrameIsCached(size_t index);
+    PassRefPtr<SkImage> cacheFrame(size_t index);
 
     // Returns the total number of bytes allocated for all framebuffers, i.e.
     // the sum of m_source.frameBytesAtIndex(...) for all frames.
     size_t totalFrameBytes();
 
-    // Called to invalidate cached data. When |destroyAll| is true, we wipe out
-    // the entire frame buffer cache and tell the image source to destroy
-    // everything; this is used when e.g. we want to free some room in the image
-    // cache. If |destroyAll| is false, we delete frames except the current
-    // frame; this is used while animating large images to keep memory footprint
-    // low; the decoder should preserve the current frame and may preserve some
-    // other frames to avoid redecoding the whole image on every frame.
-    void destroyDecodedData(bool destroyAll) override;
-
-    // If the image is large enough, calls destroyDecodedData().
-    void destroyDecodedDataIfNecessary();
-
     // Notifies observers that the memory footprint has changed.
     void notifyMemoryChanged();
 
@@ -170,6 +159,9 @@ private:
     size_t m_currentFrame; // The index of the current frame of animation.
     Vector<FrameData, 1> m_frames; // An array of the cached frames of the animation. We have to ref frames to pin them in the cache.
 
+    RefPtr<SkImage> m_frame; // One frame is cached (the most recently accessed) also for animations.
+    size_t m_frameIndex; // Index of the frame that is cached.
+
     OwnPtr<Timer<BitmapImage>> m_frameTimer;
     int m_repetitionCount; // How many total animation loops we should do.  This will be cAnimationNone if this image type is incapable of animation.
     RepetitionCountStatus m_repetitionCountStatus;