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 43aa4808b4d41f335f27f78db55217226a2d3eca..081fb369ef1cabef86c45acea0c2c4560217f5e5 100644
--- a/services/ui/ws/platform_display.h
+++ b/services/ui/ws/platform_display.h
@@ -66,11 +66,6 @@ class PlatformDisplay {
 
   virtual const display::ViewportMetrics& GetViewportMetrics() const = 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) {