Ozone: Avoid blocking in Swapbuffer Call.

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h

Index: content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h
diff --git a/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h b/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h
index e95ab7a5223e3b5353f225de5d583d44ba8c02e0..8ce161daed1165549f695b3b8b1b8d76f2b9f502 100644
--- a/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h
+++ b/content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h
@@ -5,6 +5,7 @@
 #ifndef CONTENT_BROWSER_COMPOSITOR_GPU_SURFACELESS_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_COMPOSITOR_GPU_SURFACELESS_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 
+#include "base/cancelable_callback.h"
 #include "content/browser/compositor/gpu_browser_compositor_output_surface.h"
 
 namespace content {
@@ -32,11 +33,13 @@ class GpuSurfacelessBrowserCompositorOutputSurface
   void BindFramebuffer() override;
   void Reshape(const gfx::Size& size, float scale_factor) override;
   bool BindToClient(cc::OutputSurfaceClient* client) override;
+  void OnPageFlipCompleted();
 
   unsigned int internalformat_;
   bool use_own_gl_helper_;
   scoped_ptr<GLHelper> gl_helper_;
   scoped_ptr<BufferQueue> output_surface_;
+  base::CancelableCallback<void()> page_flip_completion_callback_;

[alexst (slow to review), 2014/12/10 23:19:25]

Any specific reason you chose CancelableCallback?

 };
 
 }  // namespace content