Plumb ViewportMetrics change notifications around the world and back.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_SERVICES_VIEW_MANAGER_PUBLIC_CPP_VIEW_OBSERVER_H_
 #define MOJO_SERVICES_VIEW_MANAGER_PUBLIC_CPP_VIEW_OBSERVER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 38 matching lines @@
   virtual void OnViewDestroying(View* view) {}
   virtual void OnViewDestroyed(View* view) {}
 
   virtual void OnViewBoundsChanging(View* view,
                                     const Rect& old_bounds,
                                     const Rect& new_bounds) {}
   virtual void OnViewBoundsChanged(View* view,
                                    const Rect& old_bounds,
                                    const Rect& new_bounds) {}
 
+  virtual void OnViewViewportMetricsChanged(View* view,
+                                            const ViewportMetrics& old_bounds,
+                                            const ViewportMetrics& new_bounds) {
+  }
+
   virtual void OnCaptureChanged(View* gained_capture, View* lost_capture) {}
   virtual void OnViewFocusChanged(View* gained_focus, View* lost_focus) {}
   virtual void OnViewActivationChanged(View* gained_active, View* lost_active) {
   }
 
   virtual void OnViewInputEvent(View* view, const EventPtr& event) {}
 
   virtual void OnViewVisibilityChanging(View* view) {}
   virtual void OnViewVisibilityChanged(View* view) {}
 
@@ skipping 25 matching lines @@
   virtual void OnViewDrawnChanging(View* view) {}
   virtual void OnViewDrawnChanged(View* view) {}
 
  protected:
   virtual ~ViewObserver() {}
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_VIEW_MANAGER_PUBLIC_CPP_VIEW_OBSERVER_H_