gpu: Add EGL fence support.

ui/gl/gl_surface.h

 // Copyright (c) 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 UI_GL_GL_SURFACE_H_
 #define UI_GL_GL_SURFACE_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
@@ skipping 84 matching lines @@
   // Get the platfrom specific configuration for this surface, if available.
   virtual void* GetConfig();
 
   // Get the GL pixel format of the surface, if available.
   virtual unsigned GetFormat();
 
   // Get access to a helper providing time of recent refresh and period
   // of screen refresh. If unavailable, returns NULL.
   virtual VSyncProvider* GetVSyncProvider();
 
+  // Sets the maximum number of pending frames.
+  // Passing '0' implies no limit.
+  virtual void SetMaximumFrameLatency(unsigned int frames);
+
   // Create a GL surface that renders directly to a view.
   static scoped_refptr<GLSurface> CreateViewGLSurface(
       bool software,
       gfx::AcceleratedWidget window);
 
   // Create a GL surface used for offscreen rendering.
   static scoped_refptr<GLSurface> CreateOffscreenGLSurface(
       bool software,
       const gfx::Size& size);
 
@@ skipping 46 matching lines @@
 
  private:
   scoped_refptr<GLSurface> surface_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceAdapter);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_H_