Use the version of clang shipped with Xcode for official build

build/common.gypi

 # 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 2062 matching lines @@
         ],
         # iOS uses a whitelist to filter resources.
         'grit_whitelist%': '<(DEPTH)/build/ios/grit_whitelist.txt',
 
         # Enable host builds when generating with ninja-ios.
         'conditions': [
           ['"<(GENERATOR)"=="ninja"', {
             'host_os%': "mac",
           }],
 
+          # Use the version of clang shipped with Xcode when building official
+          # version of Chrome for iOS.
+          #
           # TODO(eugenebut): Remove enable_coverage check once
           # libclang_rt.profile_ios.a is bundled with Chromium's clang.
           # http://crbug.com/450379
-          ['enable_coverage or "<(GENERATOR)"=="xcode"', {
+          ['buildtype=="Official" or enable_coverage', {
             'clang_xcode%': 1,
           }],
         ],
       }],
       ['enable_extensions==1', {
         'grit_defines': ['-D', 'enable_extensions'],
       }],
       ['enable_plugins!=0', {
         'grit_defines': ['-D', 'enable_plugins'],
       }],
@@ skipping 3811 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }