Expose GpuMemoryBufferId through glGetImageivCHROMIUM.

third_party/WebKit/Source/platform/graphics/Canvas2DLayerBridge.h

 /*
  * Copyright (C) 2012 Google Inc. 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 138 matching lines @@
         virtual ~Logger() { }
     };
 
     void setLoggerForTesting(PassOwnPtr<Logger>);
 
 private:
 #if USE_IOSURFACE_FOR_2D_CANVAS
     // All information associated with a CHROMIUM image.
     struct ImageInfo {
         ImageInfo() {}
-        ImageInfo(GLuint imageId, GLuint textureId);
+        ImageInfo(GLuint imageId, GLuint textureId, GLint gpuMemoryBufferId);
 
         // Whether this structure holds references to a CHROMIUM image.
         bool empty();
 
         // The id of the CHROMIUM image.
         GLuint m_imageId = 0;
 
         // The id of the texture bound to the CHROMIUM image.
         GLuint m_textureId = 0;
+
+        // The id of the GpuMemoryBuffer backing the texture and CHROMIUM image.
+        GLint m_gpuMemoryBufferId = -1;
     };
 #endif // USE_IOSURFACE_FOR_2D_CANVAS
 
     struct MailboxInfo {
         DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
         WebExternalTextureMailbox m_mailbox;
         RefPtr<SkImage> m_image;
         RefPtr<Canvas2DLayerBridge> m_parentLayerBridge;
 
 #if USE_IOSURFACE_FOR_2D_CANVAS
@@ skipping 98 matching lines @@
     // Each element in this vector represents an IOSurface backed texture that
     // is ready to be reused.
     // Elements in this vector can safely be purged in low memory conditions.
     Vector<ImageInfo> m_imageInfoCache;
 #endif // USE_IOSURFACE_FOR_2D_CANVAS
 };
 
 } // namespace blink
 
 #endif