Drop frontbuffers with ui-use-gpu-process, synchronized with browser, decoupled from backbuffer dro…

content/common/gpu/texture_image_transport_surface.h

Index: content/common/gpu/texture_image_transport_surface.h
diff --git a/content/common/gpu/texture_image_transport_surface.h b/content/common/gpu/texture_image_transport_surface.h
index 907bfa4a9377600868c023618f2730b1bcd9d663..f9801b40ee4ccb07c354b70903c16ba0a9f299d6 100644
--- a/content/common/gpu/texture_image_transport_surface.h
+++ b/content/common/gpu/texture_image_transport_surface.h
@@ -48,6 +48,7 @@ class TextureImageTransportSurface :
   virtual void OnBuffersSwappedACK() OVERRIDE;
   virtual void OnPostSubBufferACK() OVERRIDE;
   virtual void OnResizeViewACK() OVERRIDE;
+  virtual void OnSetFrontSurfaceIsProtected(bool is_protected) OVERRIDE;
   virtual void OnResize(gfx::Size size) OVERRIDE;
 
   // GpuCommandBufferStub::DestructionObserver implementation.
@@ -74,9 +75,11 @@ class TextureImageTransportSurface :
 
   virtual ~TextureImageTransportSurface();
   void CreateBackTexture(const gfx::Size& size);
-  void ReleaseBackTexture();
   void AttachBackTextureToFBO();
+  void ReleaseTexture(int id);
   void ReleaseParentStub();
+  void AdjustFrontBufferAllocation();
+  int front() const { return front_; }
   int back() const { return 1 - front_; }
 
   // The framebuffer that represents this surface (service id). Allocated lazily
@@ -97,6 +100,8 @@ class TextureImageTransportSurface :
   bool backbuffer_suggested_allocation_;
   bool frontbuffer_suggested_allocation_;
 
+  bool frontbuffer_is_protected_;
+
   scoped_ptr<ImageTransportHelper> helper_;
   gfx::GLSurfaceHandle handle_;
   GpuCommandBufferStub* parent_stub_;