aura: Remove event-dispatch methods from WindowTreeHostDelegate interface.

ui/aura/remote_root_window_host_win.h

Index: ui/aura/remote_root_window_host_win.h
diff --git a/ui/aura/remote_root_window_host_win.h b/ui/aura/remote_root_window_host_win.h
index 2ac393addf5761a24f16f10c9fa9dccd87f8d0d3..0d7d7409862785360689d69fd685cd949a0b5d9e 100644
--- a/ui/aura/remote_root_window_host_win.h
+++ b/ui/aura/remote_root_window_host_win.h
@@ -14,6 +14,7 @@
 #include "ui/base/ime/remote_input_method_delegate_win.h"
 #include "ui/events/event.h"
 #include "ui/events/event_constants.h"
+#include "ui/events/event_source.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/metro_viewer/ime_types.h"
 
@@ -102,6 +103,7 @@ AURA_EXPORT void HandleMetroExit();
 // frontend process, which forwards input events to this class.
 class AURA_EXPORT RemoteWindowTreeHostWin
     : public WindowTreeHost,
+      public ui::EventSource,
       public ui::internal::RemoteInputMethodDelegateWin {
  public:
   // Returns the only RemoteWindowTreeHostWin, if this is the first time
@@ -231,6 +233,9 @@ class AURA_EXPORT RemoteWindowTreeHostWin
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void PrepareForShutdown() OVERRIDE;
 
+  // ui::EventSource:
+  virtual ui::EventProcessor* GetEventProcessor() OVERRIDE;
+
   // ui::internal::RemoteInputMethodDelegateWin overrides:
   virtual void CancelComposition() OVERRIDE;
   virtual void OnTextInputClientUpdated(