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 5275168eded9118afa9fd4963aab2e7e5878f221..eae3c45a0df4410aa2e2ab1b61a48fbd459dea4e 100644
--- a/third_party/WebKit/Source/platform/graphics/BitmapImage.h
+++ b/third_party/WebKit/Source/platform/graphics/BitmapImage.h
@@ -73,7 +73,7 @@ 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 +88,11 @@ 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.
@@ -99,6 +104,7 @@ private:
     friend class BitmapImageTest;
 
     void updateSize() const;
+    static void setAnimationCacheSizeForTesting(size_t maxCacheSize, size_t maxAnimationSizeInCache);
 
 private:

[Peter Kasting, 2016/04/28 23:07:54]

Nit: While here: It's weird to have two private: sections next to each other...
I'd combine these and ensure everything matches the Google style guide
declaration order (the enum, then constructors, then other methods, etc.).  I'd
also probably default to putting any static methods either above all or below
all non-static methods with at least one blank line between.

[aleksandar.stojiljkovic, 2016/04/29 17:17:43]

Done.

     enum RepetitionCountStatus {
@@ -123,10 +129,10 @@ private:
     ImageOrientation frameOrientationAtIndex(size_t);
 
     // Decodes and caches a frame. Never accessed except internally.
-    void cacheFrame(size_t index);
+    PassRefPtr<SkImage> cacheFrame(size_t index);
 
-    // Called before accessing m_frames[index]. Returns false on index out of bounds.
-    bool ensureFrameIsCached(size_t index);
+    // Helper method that is limiting cache size when animation frame gets cached.
+    void onAnimationFrameCached(size_t index);
 
     // Returns the total number of bytes allocated for all framebuffers, i.e.
     // the sum of m_source.frameBytesAtIndex(...) for all frames.  This is
@@ -134,18 +140,6 @@ private:
     // the values from successive calls as signed expressions.
     int 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(int delta);
 
@@ -157,6 +151,7 @@ private:
     bool shouldAnimate();
     void startAnimation(CatchUpAnimation = CatchUp) override;
     void advanceAnimation(Timer<BitmapImage>*);
+    bool shouldCacheFrame(size_t index);
 
     // Function that does the real work of advancing the animation.  When
     // skippingFrames is true, we're in the middle of a loop trying to skip over
@@ -170,6 +165,7 @@ private:
     mutable IntSize m_sizeRespectingOrientation;
 
     size_t m_currentFrame; // The index of the current frame of animation.
+    size_t m_disposeLaterFrame; // The index of the cached frame that should be disposed before accessing another one.
     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.
 
     OwnPtr<Timer<BitmapImage>> m_frameTimer;