Introduce Display Compositor mojo interface. Use InProcessContextProvider.

services/ui/ws/platform_display.h

Index: services/ui/ws/platform_display.h
diff --git a/services/ui/ws/platform_display.h b/services/ui/ws/platform_display.h
index 4c1a7d5cd11f254a68c27eb198bca2022f615058..9b64222ebb4dec5898f2c560d90c0df09815e030 100644
--- a/services/ui/ws/platform_display.h
+++ b/services/ui/ws/platform_display.h
@@ -69,11 +69,6 @@ class PlatformDisplay {
 
   virtual FrameGenerator* GetFrameGenerator() = 0;
 
-  // Notifies the PlatformDisplay that a connection to the gpu has been
-  // established.
-  virtual void OnGpuChannelEstablished(
-      scoped_refptr<gpu::GpuChannelHost> gpu_channel) = 0;
-
   // Overrides factory for testing. Default (NULL) value indicates regular
   // (non-test) environment.
   static void set_factory_for_testing(PlatformDisplayFactory* factory) {