[Mac] Delete more bookmark bar folder code. This removes things that were missed last time.

chrome/browser/ui/cocoa/bookmarks/bookmark_button_cell.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_button_cell.h"
 
 #include "base/logging.h"
 #include "base/sys_string_conversions.h"
 #import "chrome/browser/bookmarks/bookmark_model.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_button.h"
@@ skipping 53 matching lines @@
 - (id)initTextCell:(NSString*)string {
   return [self initForNode:nil contextMenu:nil cellText:string cellImage:nil];
 }
 
 // Used by the off-the-side menu, the only case where a
 // BookmarkButtonCell is loaded from a nib.
 - (void)awakeFromNib {
   [self configureBookmarkButtonCell];
 }
 
-- (BOOL)isFolderButtonCell {
-  return NO;
-}
-
 // Perform all normal init routines specific to the BookmarkButtonCell.
 - (void)configureBookmarkButtonCell {
   [self setButtonType:NSMomentaryPushInButton];
   [self setBezelStyle:NSShadowlessSquareBezelStyle];
   [self setShowsBorderOnlyWhileMouseInside:YES];
   [self setControlSize:NSSmallControlSize];
   [self setAlignment:NSLeftTextAlignment];
   [self setFont:[NSFont systemFontOfSize:[NSFont smallSystemFontSize]]];
   [self setWraps:NO];
   // NSLineBreakByTruncatingMiddle seems more common on OSX but let's
@@ skipping 112 matching lines @@
   [[self controlView] mouseEntered:event];
 }
 
 // See comment above mouseEntered:, above.
 - (void)mouseExited:(NSEvent*)event {
   [[self controlView] mouseExited:event];
   [super mouseExited:event];
 }
 
 @end