Remove a few unneeded includes

chrome/browser/ui/cocoa/tab_contents/favicon_util_mac.mm

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/cocoa/tab_contents/favicon_util_mac.h"
 
-#import <AppKit/AppKit.h>
-
-#include "base/mac/mac_util.h"
 #include "chrome/browser/favicon/favicon_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "grit/ui_resources.h"
-#include "skia/ext/skia_utils_mac.h"
-#include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/base/resource/resource_bundle.h"
-#include "ui/gfx/mac/nsimage_cache.h"
 
 namespace mac {
 
 NSImage* FaviconForTabContents(TabContents* contents) {
   if (contents && contents->favicon_tab_helper()->FaviconIsValid()) {
     NSImage* image = contents->favicon_tab_helper()->GetFavicon().ToNSImage();
     // The |image| could be nil if the bitmap is null. In that case, fallback
     // to the default image.
     if (image) {
       return image;
     }
   }
 
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   return rb.GetNativeImageNamed(IDR_DEFAULT_FAVICON);
 }
 
 }  // namespace mac