Ozone: Avoid blocking in Swapbuffer Call.

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/callback.h"
 #include "base/memory/ref_counted.h"
 #include "build/build_config.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/overlay_transform.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_f.h"
 #include "ui/gfx/size.h"
 #include "ui/gl/gl_export.h"
 #include "ui/gl/gl_implementation.h"
 
@@ skipping 101 matching lines @@
   // |crop_rect| specifies the region within the buffer to be placed inside
   // |bounds_rect|.
   virtual bool ScheduleOverlayPlane(int z_order,
                                     OverlayTransform transform,
                                     GLImage* image,
                                     const Rect& bounds_rect,
                                     const RectF& crop_rect);
 
   virtual bool IsSurfaceless() const;
 
+  typedef base::Callback<void()>
+      PageFlipCompletionCallback;
+  // On platforms where Chromium manages the system front/back buffer, we need
+  // to know when front buffer is actually displayed on screen. This
+  // callback should be called after the front buffer is displayed on screen.
+  virtual void SetPageFlipCompletionCallback(
+      const PageFlipCompletionCallback& callback);
+
   // Create a GL surface that renders directly to a view.
   static scoped_refptr<GLSurface> CreateViewGLSurface(
       gfx::AcceleratedWidget window);
 
   // Create a GL surface used for offscreen rendering.
   static scoped_refptr<GLSurface> CreateOffscreenGLSurface(
       const gfx::Size& size);
 
   static GLSurface* GetCurrent();
 
@@ skipping 41 matching lines @@
   void* GetConfig() override;
   unsigned GetFormat() override;
   VSyncProvider* GetVSyncProvider() override;
   bool ScheduleOverlayPlane(int z_order,
                             OverlayTransform transform,
                             GLImage* image,
                             const Rect& bounds_rect,
                             const RectF& crop_rect) override;
   bool IsSurfaceless() const override;
 
+  void SetPageFlipCompletionCallback(
+      const PageFlipCompletionCallback& callback) override;
+
   GLSurface* surface() const { return surface_.get(); }
 
  protected:
   ~GLSurfaceAdapter() override;
 
  private:
   scoped_refptr<GLSurface> surface_;
 
   DISALLOW_COPY_AND_ASSIGN(GLSurfaceAdapter);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_H_