Revert of Makes change_id unsigned

mojo/services/view_manager/view_manager_connection.h

Index: mojo/services/view_manager/view_manager_connection.h
diff --git a/mojo/services/view_manager/view_manager_connection.h b/mojo/services/view_manager/view_manager_connection.h
index 02bfa528195f330bbe22b4301e17ee588b3ef03a..974e0332c2848554f79d6cbe69d223d99f102e3d 100644
--- a/mojo/services/view_manager/view_manager_connection.h
+++ b/mojo/services/view_manager/view_manager_connection.h
@@ -10,7 +10,6 @@
 #include "base/basictypes.h"
 #include "mojo/public/cpp/shell/service.h"
 #include "mojo/services/public/interfaces/view_manager/view_manager.mojom.h"
-#include "mojo/services/view_manager/ids.h"
 #include "mojo/services/view_manager/node_delegate.h"
 #include "mojo/services/view_manager/view_manager_export.h"
 
@@ -48,11 +47,11 @@
   void NotifyNodeHierarchyChanged(const NodeId& node,
                                   const NodeId& new_parent,
                                   const NodeId& old_parent,
-                                  ChangeId change_id);
+                                  int32_t change_id);
   void NotifyNodeViewReplaced(const NodeId& node,
                               const ViewId& new_view_id,
                               const ViewId& old_view_id,
-                              ChangeId change_id);
+                              int32_t change_id);
 
  private:
   typedef std::map<uint16_t, Node*> NodeMap;
@@ -62,41 +61,41 @@
   // is the connection that originated the change.
   bool DeleteNodeImpl(ViewManagerConnection* source,
                       const NodeId& node_id,
-                      ChangeId change_id);
+                      int32_t change_id);
 
   // Deletes a view owned by this connection. Returns true on success. |source|
   // is the connection that originated the change.
   bool DeleteViewImpl(ViewManagerConnection* source,
                       const ViewId& view_id,
-                      ChangeId change_id);
+                      int32_t change_id);
 
   // Sets the view associated with a node.
   bool SetViewImpl(const NodeId& node_id,
                    const ViewId& view_id,
-                   ChangeId change_id);
+                   int32_t change_id);
 
   // Overridden from ViewManager:
   virtual void CreateNode(uint16_t node_id,
                           const Callback<void(bool)>& callback) OVERRIDE;
   virtual void DeleteNode(uint32_t transport_node_id,
-                          ChangeId change_id,
+                          int32_t change_id,
                           const mojo::Callback<void(bool)>& callback) OVERRIDE;
   virtual void AddNode(uint32_t parent_id,
                        uint32_t child_id,
-                       ChangeId change_id,
+                       int32_t change_id,
                        const Callback<void(bool)>& callback) OVERRIDE;
   virtual void RemoveNodeFromParent(
       uint32_t node_id,
-      ChangeId change_id,
+      int32_t change_id,
       const Callback<void(bool)>& callback) OVERRIDE;
   virtual void CreateView(uint16_t view_id,
                           const mojo::Callback<void(bool)>& callback) OVERRIDE;
   virtual void DeleteView(uint32_t transport_view_id,
-                          ChangeId change_id,
+                          int32_t change_id,
                           const mojo::Callback<void(bool)>& callback) OVERRIDE;
   virtual void SetView(uint32_t transport_node_id,
                        uint32_t transport_view_id,
-                       ChangeId change_id,
+                       int32_t change_id,
                        const mojo::Callback<void(bool)>& callback) OVERRIDE;
 
   // Overriden from NodeDelegate: