Fixing laggy chrome on a multitude of accelerated canvases

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

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 113 matching lines @@
     void flush(); // process deferred draw commands immediately
     void flushGpu(); // Like flush(), but flushes all the way down to the Gpu context if the surface is accelerated
 
     void notifySurfaceInvalid();
 
     PassRefPtr<SkImage> newSkImageSnapshot(AccelerationHint) const;
     PassRefPtr<Image> newImageSnapshot(AccelerationHint = PreferNoAcceleration) const;
 
     void draw(GraphicsContext*, const FloatRect&, const FloatRect*, SkXfermode::Mode);
 
+    void updateGPUMemoryUsage() const;
+    static intptr_t getGlobalGPUMemoryUsage() { return s_globalGPUMemoryUsage; }
+    intptr_t getGPUMemoryUsage() { return m_gpuMemoryUsage; }
+
 private:
     ImageBuffer(PassOwnPtr<ImageBufferSurface>);
 
     enum SnapshotState {
         InitialSnapshotState,
         DidAcquireSnapshot,
         DrawnToAfterSnapshot,
     };
     mutable SnapshotState m_snapshotState;
     OwnPtr<ImageBufferSurface> m_surface;
     ImageBufferClient* m_client;
+
+    mutable intptr_t m_gpuMemoryUsage;
+    static intptr_t s_globalGPUMemoryUsage;
 };
 
 struct ImageDataBuffer {
     STACK_ALLOCATED();
     ImageDataBuffer(const IntSize& size, const unsigned char* data) : m_data(data), m_size(size) { }
     String PLATFORM_EXPORT toDataURL(const String& mimeType, const double& quality) const;
     bool PLATFORM_EXPORT encodeImage(const String& mimeType, const double& quality, Vector<unsigned char>* encodedImage) const;
     const unsigned char* pixels() const { return m_data; }
     int height() const { return m_size.height(); }
     int width() const { return m_size.width(); }
 
     const unsigned char* m_data;
     const IntSize m_size;
 };
 
 } // namespace blink
 
 #endif // ImageBuffer_h