Plumb ViewportMetrics change notifications around the world and back.

services/view_manager/server_view_delegate.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 SERVICES_VIEW_MANAGER_SERVER_VIEW_DELEGATE_H_
 #define SERVICES_VIEW_MANAGER_SERVER_VIEW_DELEGATE_H_
 
 #include "mojo/services/view_manager/public/interfaces/view_manager_constants.mojom.h"
 
 namespace gfx {
 class Rect;
 }
 
+namespace mojo {
+class ViewportMetrics;
+}
+
 namespace view_manager {
 
 class ServerView;
 
 class ServerViewDelegate {
  public:
   // Invoked when a view is about to be destroyed; before any of the children
   // have been removed and before the view has been removed from its parent.
   virtual void OnWillDestroyView(ServerView* view) = 0;
 
   // Invoked at the end of the View's destructor (after it has been removed from
   // the hierarchy).
   virtual void OnViewDestroyed(const ServerView* view) = 0;
 
   virtual void OnWillChangeViewHierarchy(ServerView* view,
                                          ServerView* new_parent,
                                          ServerView* old_parent) = 0;
 
   virtual void OnViewHierarchyChanged(const ServerView* view,
                                       const ServerView* new_parent,
                                       const ServerView* old_parent) = 0;
 
   virtual void OnViewBoundsChanged(const ServerView* view,
                                    const gfx::Rect& old_bounds,
                                    const gfx::Rect& new_bounds) = 0;
 
+  virtual void OnViewViewportMetricsChanged(
+      const ServerView* view,
+      const mojo::ViewportMetrics& old_metrics,
+      const mojo::ViewportMetrics& new_metrics) = 0;
+
   virtual void OnViewSurfaceIdChanged(const ServerView* view) = 0;
 
   virtual void OnViewReordered(const ServerView* view,
                                const ServerView* relative,
                                mojo::OrderDirection direction) = 0;
 
   virtual void OnWillChangeViewVisibility(ServerView* view) = 0;
 
   virtual void OnViewSharedPropertyChanged(
       const ServerView* view,
       const std::string& name,
       const std::vector<uint8_t>* new_data) = 0;
 
   virtual void OnScheduleViewPaint(const ServerView* view) = 0;
 
  protected:
   virtual ~ServerViewDelegate() {}
 };
 
 }  // namespace view_manager
 
 #endif  // SERVICES_VIEW_MANAGER_SERVER_VIEW_DELEGATE_H_