Remove DispositionChangePhase.

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 9e189fd609eff7199dc7a31c42da92cd09a75b52..2eb311145fbb14fa3fc2b9e6316772127bd31ac5 100644
--- a/mojo/services/public/cpp/view_manager/view_observer.h
+++ b/mojo/services/public/cpp/view_manager/view_observer.h
@@ -16,14 +16,12 @@ namespace view_manager {
 
 class View;
 
+// See note about -ing/-ed suffixes for observer methods in node_observer.h.
+
 class ViewObserver {
  public:
-  enum DispositionChangePhase {
-    DISPOSITION_CHANGING,
-    DISPOSITION_CHANGED
-  };
-
-  virtual void OnViewDestroy(View* view, DispositionChangePhase phase) {}
+  virtual void OnViewDestroying(View* view) {}
+  virtual void OnViewDestroyed(View* view) {}
 
   virtual void OnViewInputEvent(View* view, const EventPtr& event) {}