cc: Partial draw without partial swap support.

cc/output/output_surface.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_OUTPUT_OUTPUT_SURFACE_H_
 #define CC_OUTPUT_OUTPUT_SURFACE_H_
 
 #include <deque>
 #include <memory>
 
@@ skipping 100 matching lines @@
 
   // Gives the GL internal format that should be used for calling CopyTexImage2D
   // when the framebuffer is bound via BindFramebuffer().
   virtual uint32_t GetFramebufferCopyTextureFormat() = 0;
 
   // Swaps the current backbuffer to the screen. For successful swaps, the
   // implementation must call OutputSurfaceClient::DidReceiveSwapBuffersAck()
   // after returning from this method in order to unblock the next frame.
   virtual void SwapBuffers(OutputSurfaceFrame frame) = 0;
 
+  // If this returns true, then partial draw of |damage| rect is supported
+  // by surface.
+  virtual bool CanPartialDraw(const gfx::Rect& damage) = 0;
+
  protected:
   struct OutputSurface::Capabilities capabilities_;
   scoped_refptr<ContextProvider> context_provider_;
   scoped_refptr<VulkanContextProvider> vulkan_context_provider_;
   std::unique_ptr<SoftwareOutputDevice> software_device_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(OutputSurface);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OUTPUT_SURFACE_H_