[Mac]Implement ViewID support.

chrome/browser/cocoa/tab_controller_target.h

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 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 CHROME_BROWSER_COCOA_TAB_CONTROLLER_TARGET_H_
 #define CHROME_BROWSER_COCOA_TAB_CONTROLLER_TARGET_H_
 
 #include "chrome/browser/tabs/tab_strip_model.h"
 
 @class TabController;
 
 // A protocol to be implemented by a TabController's target.
 @protocol TabControllerTarget
 - (void)selectTab:(id)sender;
 - (void)closeTab:(id)sender;
 
 // Dispatch context menu commands for the given tab controller.
 - (void)commandDispatch:(TabStripModel::ContextMenuCommand)command
           forController:(TabController*)controller;
 // Returns YES if the specificed command should be enabled for the given
 // controller.
 - (BOOL)isCommandEnabled:(TabStripModel::ContextMenuCommand)command
            forController:(TabController*)controller;
+// Returns the index of the tab controller. Returns -1 if not present.
+// Total number of tab controllers owned by the target will be returned
+// in |*total|;
+- (NSInteger)indexForTabController:(TabController*)controller
+                           inTotal:(NSInteger*)total;
 @end
 
 #endif  // CHROME_BROWSER_COCOA_TAB_CONTROLLER_TARGET_H_