ozone: gpu: Add plumbing for platform-specific gpu messaging

ui/ozone/ozone_platform.h

Index: ui/ozone/ozone_platform.h
diff --git a/ui/ozone/ozone_platform.h b/ui/ozone/ozone_platform.h
index e6e2e0e610f13f3bf8c7498f70cad04ba5c28248..1ada25e314d9c72f5b1c4f82dddbc57a8ca19c4d 100644
--- a/ui/ozone/ozone_platform.h
+++ b/ui/ozone/ozone_platform.h
@@ -18,6 +18,8 @@ class CursorFactoryOzone;
 class EventFactoryOzone;
 class NativeDisplayDelegate;
 class TouchscreenDeviceManager;
+class GpuPlatformSupport;
+class GpuPlatformSupportHost;
 
 // Base class for Ozone platform implementations.
 //
@@ -53,6 +55,8 @@ class OZONE_EXPORT OzonePlatform {
   virtual gfx::SurfaceFactoryOzone* GetSurfaceFactoryOzone() = 0;
   virtual ui::EventFactoryOzone* GetEventFactoryOzone() = 0;
   virtual ui::CursorFactoryOzone* GetCursorFactoryOzone() = 0;
+  virtual ui::GpuPlatformSupport* GetGpuPlatformSupport() = 0;
+  virtual ui::GpuPlatformSupportHost* GetGpuPlatformSupportHost() = 0;
 #if defined(OS_CHROMEOS)
   virtual scoped_ptr<ui::NativeDisplayDelegate>
       CreateNativeDisplayDelegate() = 0;