[Mac]Implement ViewID support.

chrome/browser/cocoa/bookmark_bar_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/bookmark_bar_view.h"
 
 #include "chrome/browser/bookmarks/bookmark_pasteboard_helper_mac.h"
 #import "chrome/browser/browser_theme_provider.h"
 #import "chrome/browser/cocoa/bookmark_bar_controller.h"
 #import "chrome/browser/cocoa/bookmark_button.h"
 #import "chrome/browser/cocoa/bookmark_folder_target.h"
 #import "chrome/browser/cocoa/themed_window.h"
+#import "chrome/browser/cocoa/view_id_util.h"
 #import "third_party/mozilla/NSPasteboard+Utils.h"
 
 @interface BookmarkBarView (Private)
 - (void)themeDidChangeNotification:(NSNotification*)aNotification;
 - (void)updateTheme:(ThemeProvider*)themeProvider;
 @end
 
 @implementation BookmarkBarView
 
 @synthesize dropIndicatorShown = dropIndicatorShown_;
@@ skipping 219 matching lines @@
     if ([self performDragOperationForURL:info])
       return YES;
   }
   return NO;
 }
 
 - (void)setController:(id)controller {
   controller_ = controller;
 }
 
+// Tag is used solely for ViewID. Override to prevent changing of it.
+- (NSInteger)tag {
+  return view_id_util::ViewIDToTag(VIEW_ID_BOOKMARK_BAR);
+}
+
 @end  // @implementation BookmarkBarView