ozone: gbm: Add overlay support

ui/ozone/platform/dri/gbm_surface_factory.h

Index: ui/ozone/platform/dri/gbm_surface_factory.h
diff --git a/ui/ozone/platform/dri/gbm_surface_factory.h b/ui/ozone/platform/dri/gbm_surface_factory.h
index c07852657233634f0d9d50112931f3bb358c5cf0..a8a0c4c8cc43e1fa7d61d0aa59d47de89eda5273 100644
--- a/ui/ozone/platform/dri/gbm_surface_factory.h
+++ b/ui/ozone/platform/dri/gbm_surface_factory.h
@@ -13,7 +13,7 @@ namespace ui {
 
 class GbmSurfaceFactory : public DriSurfaceFactory {
  public:
-  GbmSurfaceFactory();
+  GbmSurfaceFactory(bool allow_surfaceless);
   virtual ~GbmSurfaceFactory();
 
   void InitializeGpu(DriWrapper* dri,
@@ -32,9 +32,11 @@ class GbmSurfaceFactory : public DriSurfaceFactory {
   virtual scoped_refptr<ui::NativePixmap> CreateNativePixmap(
       gfx::Size size,
       BufferFormat format) OVERRIDE;
+  virtual bool CanShowPrimaryPlaneAsOverlay() OVERRIDE;
 
  private:
   gbm_device* device_;  // Not owned.
+  bool allow_surfaceless_;
 
   DISALLOW_COPY_AND_ASSIGN(GbmSurfaceFactory);
 };