Subrect snapshot support.

content/browser/renderer_host/compositor_impl_android.h

Index: content/browser/renderer_host/compositor_impl_android.h
diff --git a/content/browser/renderer_host/compositor_impl_android.h b/content/browser/renderer_host/compositor_impl_android.h
index 1514fcf5172ff1821944ea522ee995840cce49a5..2312ce981dba2cdb4173392005b1810db3b6615f 100644
--- a/content/browser/renderer_host/compositor_impl_android.h
+++ b/content/browser/renderer_host/compositor_impl_android.h
@@ -55,7 +55,10 @@ class CONTENT_EXPORT CompositorImpl
   virtual WebKit::WebGLId GenerateCompressedTexture(
       gfx::Size& size, int data_size, void* data) OVERRIDE;
   virtual void DeleteTexture(WebKit::WebGLId texture_id) OVERRIDE;
+  // |sub_rect| should be the same size as |bitmap|.  This just lets the caller
+  // specify which piece of the texture to copy.
   virtual void CopyTextureToBitmap(WebKit::WebGLId texture_id,
+                                   const gfx::Rect& sub_rect,
                                    gfx::JavaBitmap& bitmap) OVERRIDE;
 
   // LayerTreeHostClient implementation.