Update view_manager and window_manager to make use of content handling.

mojo/services/view_manager/view_manager_service_impl.h

Index: mojo/services/view_manager/view_manager_service_impl.h
diff --git a/mojo/services/view_manager/view_manager_service_impl.h b/mojo/services/view_manager/view_manager_service_impl.h
index e805387efc89249c3c92f7cb584522ec1b39fe6b..f505622c2d5a770a98ebb21ac7d7402fb1491910 100644
--- a/mojo/services/view_manager/view_manager_service_impl.h
+++ b/mojo/services/view_manager/view_manager_service_impl.h
@@ -119,11 +119,6 @@ class MOJO_VIEW_MANAGER_EXPORT ViewManagerServiceImpl
   void RemoveFromKnown(const ServerView* view,
                        std::vector<ServerView*>* local_views);
 
-  // Adds |view_id| to the set of roots this connection knows about. The caller
-  // should have verified |view_id| is not among the roots of this connection.
-  void AddRoot(const ViewId& view_id,
-               InterfaceRequest<ServiceProvider> service_provider);
-
   // Removes |view_id| from the set of roots this connection knows about.
   void RemoveRoot(const ViewId& view_id);