gyp performance: Add a DoMain version of build/compiler_version

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 1346 matching lines @@
             # We directly set the gcc_version since we know what we use.
             'conditions': [
               ['target_arch=="x64" or target_arch=="arm64"', {
                 'gcc_version%': 48,
               }, {
                 'gcc_version%': 46,
               }],
             ],
             'binutils_version%': 222,
           }, {
-            'gcc_version%': '<!(python <(DEPTH)/build/compiler_version.py)',
-            'binutils_version%': '<!(python <(DEPTH)/build/compiler_version.py assembler)',
+            'gcc_version%': '<!pymod_do_main(compiler_version)',
+            'binutils_version%': '<!pymod_do_main(compiler_version assembler)',
           }],
         ],
       }, {
         'gcc_version%': 0,
         'binutils_version%': 0,
       }],
       ['OS=="win" and "<!(python <(DEPTH)/build/dir_exists.py <(windows_sdk_default_path))"=="True"', {
         'windows_sdk_path%': '<(windows_sdk_default_path)',
       }, {
         'windows_sdk_path%': 'C:/Program Files (x86)/Windows Kits/8.0',
@@ skipping 3831 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',
   },
 }