Add a couple UIKit util functions in src/ui/ios/

ui/ios/ui_ios.gyp

 # Copyright 2014 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'ui_ios',
       'type': 'static_library',
       # Linkable dependents need to set the linker flag '-ObjC' in order to use
       # the categories in this target (e.g. NSString+CrStringDrawing.h).
       'link_settings': {
         'xcode_settings': {'OTHER_LDFLAGS': ['-ObjC']},
       },
       'include_dirs': [
         '../..',
       ],
       'sources': [
         'NSString+CrStringDrawing.h',
         'NSString+CrStringDrawing.mm',
+        'uikit_util.h',
+        'uikit_util.mm',
       ],
     },
   ],
 }