ozone: gbm: Add overlay support

ui/ozone/platform/dri/gbm_surface.h

 // Copyright 2014 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_OZONE_PLATFORM_DRI_GBM_SURFACE_H_
 #define UI_OZONE_PLATFORM_DRI_GBM_SURFACE_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/geometry/size.h"
@@ skipping 14 matching lines @@
 class GbmSurface : public ScanoutSurface {
  public:
   GbmSurface(gbm_device* device, DriWrapper* dri, const gfx::Size& size);
   virtual ~GbmSurface();
 
   // ScanoutSurface:
   virtual bool Initialize() OVERRIDE;
   virtual uint32_t GetFramebufferId() const OVERRIDE;
   virtual uint32_t GetHandle() const OVERRIDE;
   virtual gfx::Size Size() const OVERRIDE;
+  virtual void PreSwapBuffers() OVERRIDE;
   virtual void SwapBuffers() OVERRIDE;
 
   // Before scheduling the backbuffer to be scanned out we need to "lock" it.
   // When we lock it, GBM will give a pointer to a buffer representing the
   // backbuffer. It will also update its information on which buffers can not be
   // used for drawing. The buffer will be released when the page flip event
   // occurs (see SwapBuffers). This is called from GbmSurfaceFactory before
   // scheduling a page flip.
   void LockCurrentDrawable();
 
@@ skipping 21 matching lines @@
   // before an actual window is created and draws. So, we create a dumb buffer
   // for this purpose.
   scoped_ptr<DriBuffer> dumb_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(GbmSurface);
 };
 
 }  // namespace ui
 
 #endif  // UI_OZONE_PLATFORM_DRI_GBM_SURFACE_H_