Disable pyauto for Win64 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 1012 matching lines @@
       }, {
         'windows_sdk_path%': 'C:/Program Files (x86)/Windows Kits/8.0',
       }],
       ['OS=="win" and "<!(python <(DEPTH)/build/dir_exists.py <(directx_sdk_default_path))"=="True"', {
         'directx_sdk_path%': '<(directx_sdk_default_path)',
       }, {
         'directx_sdk_path%': '$(DXSDK_DIR)',
       }],
       ['OS=="win"', {
         'windows_driver_kit_path%': '$(WDK_DIR)',
+        # Set the python arch to prevent conflicts with pyauto on Win64 build.
+        # TODO(jschuh): crbug.com/177664 Investigate Win64 pyauto build.
+        'python_arch%': 'ia32',
       }],
       # If use_official_google_api_keys is already set (to 0 or 1), we
       # do none of the implicit checking.  If it is set to 1 and the
       # internal keys file is missing, the build will fail at compile
       # time.  If it is set to 0 and keys are not provided by other
       # means, a warning will be printed at compile time.
       ['use_official_google_api_keys==2', {
         'use_official_google_api_keys%':
             '<!(python <(DEPTH)/google_apis/build/check_internal.py <(DEPTH)/google_apis/internal/google_chrome_api_keys.h)',
       }],
@@ skipping 3058 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',
   },
 }