aura: Remove event-dispatch methods from WindowTreeHostDelegate interface.

mojo/examples/aura_demo/root_window_host_mojo.h

Index: mojo/examples/aura_demo/root_window_host_mojo.h
diff --git a/mojo/examples/aura_demo/root_window_host_mojo.h b/mojo/examples/aura_demo/root_window_host_mojo.h
index d75bfde66892b171ea67c19dc1570e6ebb7ab4f2..6333a54e36a0f16655e37c6168963e4b5bd4b5b0 100644
--- a/mojo/examples/aura_demo/root_window_host_mojo.h
+++ b/mojo/examples/aura_demo/root_window_host_mojo.h
@@ -9,6 +9,7 @@
 #include "mojo/public/bindings/remote_ptr.h"
 #include "mojom/native_viewport.h"
 #include "ui/aura/window_tree_host.h"
+#include "ui/events/event_source.h"
 #include "ui/gfx/rect.h"
 
 namespace ui {
@@ -21,6 +22,7 @@ namespace examples {
 class GLES2ClientImpl;
 
 class WindowTreeHostMojo : public aura::WindowTreeHost,
+                           public ui::EventSource,
                            public NativeViewportClient {
  public:
   WindowTreeHostMojo(ScopedMessagePipeHandle viewport_handle,
@@ -55,6 +57,9 @@ class WindowTreeHostMojo : public aura::WindowTreeHost,
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void PrepareForShutdown() OVERRIDE;
 
+  // ui::EventSource:
+  virtual ui::EventProcessor* GetEventProcessor() OVERRIDE;
+
   // Overridden from NativeViewportClient:
   virtual void OnCreated() MOJO_OVERRIDE;
   virtual void OnDestroyed() OVERRIDE;