Mac: Fix theme image drawing when building with >=10.9 SDK.

chrome/chrome_browser_ui.gypi

 # Copyright 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.
 
 {
   'variables': {
     'chrome_browser_ui_non_ios_sources': [
       'browser/ui/accelerator_utils.h',
       'browser/ui/android/android_about_app_info.cc',
       'browser/ui/android/android_about_app_info.h',
@@ skipping 687 matching lines @@
       'browser/ui/cocoa/tab_contents/web_drag_bookmark_handler_mac.h',
       'browser/ui/cocoa/tab_contents/web_drag_bookmark_handler_mac.mm',
       'browser/ui/cocoa/tab_modal_confirm_dialog_mac.h',
       'browser/ui/cocoa/tab_modal_confirm_dialog_mac.mm',
       'browser/ui/cocoa/table_row_nsimage_cache.h',
       'browser/ui/cocoa/table_row_nsimage_cache.mm',
       'browser/ui/cocoa/tabs/media_indicator_view.h',
       'browser/ui/cocoa/tabs/media_indicator_view.mm',
       'browser/ui/cocoa/tabs/tab_controller.h',
       'browser/ui/cocoa/tabs/tab_controller.mm',
+      'browser/ui/cocoa/tabs/tab_strip_background_view.h',
+      'browser/ui/cocoa/tabs/tab_strip_background_view.mm',
       'browser/ui/cocoa/tabs/tab_strip_controller.h',
       'browser/ui/cocoa/tabs/tab_strip_controller.mm',
       'browser/ui/cocoa/tabs/tab_strip_drag_controller.h',
       'browser/ui/cocoa/tabs/tab_strip_drag_controller.mm',
       'browser/ui/cocoa/tabs/tab_strip_model_observer_bridge.h',
       'browser/ui/cocoa/tabs/tab_strip_model_observer_bridge.mm',
       'browser/ui/cocoa/tabs/tab_strip_view.h',
       'browser/ui/cocoa/tabs/tab_strip_view.mm',
       'browser/ui/cocoa/tabs/tab_view.h',
       'browser/ui/cocoa/tabs/tab_view.mm',
@@ skipping 2263 matching lines @@
         }],
         ['OS!="android" and OS!="ios"', {
           'dependencies': [
             '../device/bluetooth/bluetooth.gyp:device_bluetooth',
           ],
         }],
       ],
     },
   ],
 }