[Mac]Implement ViewID support.

chrome/browser/cocoa/toolbar_view.mm

-  // 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.
 
 #import "chrome/browser/cocoa/toolbar_view.h"
 
 #import "chrome/browser/cocoa/themed_window.h"
+#import "chrome/browser/cocoa/view_id_util.h"
 
 @implementation ToolbarView
 
 @synthesize dividerOpacity = dividerOpacity_;
 
 // Prevent mouse down events from moving the parent window around.
 - (BOOL)mouseDownCanMoveWindow {
   return NO;
 }
 
@@ skipping 14 matching lines @@
   return NO;
 }
 
 - (id)accessibilityAttributeValue:(NSString*)attribute {
   if ([attribute isEqual:NSAccessibilityRoleAttribute])
     return NSAccessibilityToolbarRole;
 
   return [super accessibilityAttributeValue:attribute];
 }
 
+// Tag is used solely for ViewID. Override to prevent changing of it.
+- (NSInteger)tag {
+  return view_id_util::ViewIDToTag(VIEW_ID_TOOLBAR);
+}
+
 @end