Revert of Makes change_id unsigned

mojo/services/view_manager/root_node_manager.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_ROOT_NODE_MANAGER_H_
 #define MOJO_SERVICES_VIEW_MANAGER_ROOT_NODE_MANAGER_H_
 
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 14 matching lines @@
 class MOJO_VIEW_MANAGER_EXPORT RootNodeManager
     : public NativeViewportClient,
       public NodeDelegate {
  public:
   // Create when a ViewManagerConnection is about to make a change. Ensures
   // clients are notified of the correct change id.
   class ScopedChange {
    public:
     ScopedChange(ViewManagerConnection* connection,
                  RootNodeManager* root,
-                 ChangeId change_id);
+                 int32_t change_id);
     ~ScopedChange();
 
    private:
     RootNodeManager* root_;
 
     DISALLOW_COPY_AND_ASSIGN(ScopedChange);
   };
 
   RootNodeManager();
   virtual ~RootNodeManager();
@@ skipping 18 matching lines @@
   void NotifyNodeHierarchyChanged(const NodeId& node,
                                   const NodeId& new_parent,
                                   const NodeId& old_parent);
   void NotifyNodeViewReplaced(const NodeId& node,
                               const ViewId& new_view_id,
                               const ViewId& old_view_id);
 
  private:
   // Tracks a change.
   struct Change {
-    Change(int32_t connection_id, ChangeId change_id)
+    Change(int32_t connection_id, int32_t change_id)
         : connection_id(connection_id),
           change_id(change_id) {
     }
 
     int32_t connection_id;
-    ChangeId change_id;
+    int32_t change_id;
   };
 
   typedef std::map<uint16_t, ViewManagerConnection*> ConnectionMap;
 
   // Invoked when a particular connection is about to make a change. Records
   // the |change_id| so that it can be supplied to the clients by way of
   // OnNodeHierarchyChanged().
   // Changes should never nest, meaning each PrepareForChange() must be
   // balanced with a call to FinishChange() with no PrepareForChange()
   // in between.
-  void PrepareForChange(ViewManagerConnection* connection, ChangeId change_id);
+  void PrepareForChange(ViewManagerConnection* connection, int32_t change_id);
 
   // Balances a call to PrepareForChange().
   void FinishChange();
 
   // Overridden from NativeViewportClient:
   virtual void OnCreated() OVERRIDE;
   virtual void OnDestroyed() OVERRIDE;
   virtual void OnBoundsChanged(const Rect& bounds) OVERRIDE;
   virtual void OnEvent(const Event& event,
                        const mojo::Callback<void()>& callback) OVERRIDE;
@@ skipping 19 matching lines @@
   scoped_ptr<Change> change_;
 
   DISALLOW_COPY_AND_ASSIGN(RootNodeManager);
 };
 
 }  // namespace view_manager
 }  // namespace services
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_VIEW_MANAGER_ROOT_NODE_MANAGER_H_