Fix official build due to 2x.pak reference

chrome/tools/build/win/FILES.cfg

 # -*- python -*-
 # ex: set syntax=python:
 
 # 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.
 
 # This is a buildbot configuration file containing a tagged list of files
 # processed by the stage/archive scripts. The known tags are:
 #
@@ skipping 334 matching lines @@
     'filename': 'resources.pak',
     'arch': ['32bit', '64bit'],
     'buildtype': ['dev', 'official'],
   },
   {
     'filename': 'theme_resources_standard.pak',
     'arch': ['32bit', '64bit'],
     'buildtype': ['dev', 'official'],
   },
   {
+    'filename': 'theme_resources_2x.pak',
+    'arch': ['32bit', '64bit'],
+    'buildtype': ['dev', 'official'],
+    'optional': ['dev', 'official'],
+  },
+  {
     'filename': 'theme_resources_metro_1x.pak',
     'arch': ['32bit', '64bit'],
     'buildtype': ['dev', 'official'],
+    'optional': ['dev', 'official'],
   },
   {
     'filename': 'ui_resources_standard.pak',
     'arch': ['32bit', '64bit'],
     'buildtype': ['dev', 'official'],
   },
   {
+    'filename': 'ui_resources_2x.pak',
+    'arch': ['32bit', '64bit'],
+    'buildtype': ['dev', 'official'],
+    'optional': ['dev', 'official'],
+  },
+  {
     'filename': 'wow_helper.exe',
     'arch': ['32bit', '64bit'],
     'buildtype': ['dev', 'official'],
   },
   # Flash Player files:
   {
     'filename': 'gcswf32.dll',
     'arch': ['32bit', '64bit'],
     'buildtype': ['official'],
   },
@@ skipping 372 matching lines @@
     'filegroup': ['symbols'],
   },
   {
     'filename': 'syzygy/mini_installer.pdb',
     'arch': ['32bit', '64bit'],
     'buildtype': ['official'],
     'archive': 'chrome-win32-syms.zip',
     'filegroup': ['symbols'],
   },
 ]