Wire input events through the ViewManagerClient interface.

mojo/services/public/cpp/view_manager/view_observer.h

Index: mojo/services/public/cpp/view_manager/view_observer.h
diff --git a/mojo/services/public/cpp/view_manager/view_observer.h b/mojo/services/public/cpp/view_manager/view_observer.h
index a2a634343fe7df4fe8d1d72887308bc9df98dad3..2e3571d59a77d3d7f53a44c5ab0b467fded04301 100644
--- a/mojo/services/public/cpp/view_manager/view_observer.h
+++ b/mojo/services/public/cpp/view_manager/view_observer.h
@@ -9,6 +9,8 @@
 
 #include "base/basictypes.h"
 
+#include "mojo/services/public/interfaces/input_events/input_events.mojom.h"
+
 namespace mojo {
 namespace view_manager {
 
@@ -23,6 +25,8 @@ class ViewObserver {
 
   virtual void OnViewDestroy(View* view, DispositionChangePhase phase) {}
 
+  virtual void OnViewInputEvent(View* view, EventPtr event) {}
+
  protected:
   virtual ~ViewObserver() {}
 };