Makes ViewManagerServiceImpl track a single root

mojo/services/view_manager/default_access_policy.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_DEFAULT_ACCESS_POLICY_H_
 #define MOJO_SERVICES_VIEW_MANAGER_DEFAULT_ACCESS_POLICY_H_
 
 #include "base/basictypes.h"
 #include "mojo/services/view_manager/access_policy.h"
 
@@ skipping 23 matching lines @@
   bool CanChangeViewVisibility(const ServerView* view) const override;
   bool CanSetViewSurfaceId(const ServerView* view) const override;
   bool CanSetViewBounds(const ServerView* view) const override;
   bool CanSetViewProperties(const ServerView* view) const override;
   bool ShouldNotifyOnHierarchyChange(
       const ServerView* view,
       const ServerView** new_parent,
       const ServerView** old_parent) const override;
 
  private:
-  bool IsViewInRoots(const ServerView* view) const;
-
   bool WasCreatedByThisConnection(const ServerView* view) const;
 
   const ConnectionSpecificId connection_id_;
   AccessPolicyDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultAccessPolicy);
 };
 
 }  // namespace service
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_VIEW_MANAGER_DEFAULT_ACCESS_POLICY_H_