[Mac] Remove unnecessary subclasses in bookmark bar

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_view_cocoa.mm

 // Copyright (c) 2011 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/ui/cocoa/bookmarks/bookmark_bar_view_cocoa.h"
 
 #include "chrome/browser/profiles/profile.h"
 #import "chrome/browser/themes/theme_properties.h"
 #import "chrome/browser/themes/theme_service.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_bar_controller.h"
@@ skipping 95 matching lines @@
       themeProvider->GetNSColor(ThemeProperties::COLOR_BOOKMARK_TEXT);
   [noItemTextfield_ setTextColor:color];
 }
 
 // Mouse down events on the bookmark bar should not allow dragging the parent
 // window around.
 - (BOOL)mouseDownCanMoveWindow {
   return NO;
 }
 
-- (BookmarkBarTextField*)noItemTextfield {
+- (NSTextField*)noItemTextfield {
   return noItemTextfield_;
 }
 
 - (NSButton*)importBookmarksButton {
   return importBookmarksButton_;
 }
 
 - (BookmarkBarController*)controller {
   return controller_;
 }
@@ skipping 156 matching lines @@
 
 - (void)setController:(id)controller {
   controller_ = controller;
 }
 
 - (ViewID)viewID {
   return VIEW_ID_BOOKMARK_BAR;
 }
 
 @end  // @implementation BookmarkBarView
-
-@implementation BookmarkBarTextField
-
-- (NSMenu*)menu {
-  return [barView_ menu];
-}
-
-@end  // @implementation BookmarkBarTextField
-
-@implementation BookmarkBarItemContainer
-
-- (NSMenu*)menu {
-  return [barView_ menu];
-}
-
-@end  // @implementation BookmarkBarItemContainer