Hook up gomadir in the GN build.

build/gyp_chromium

 #!/usr/bin/env 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 script is wrapper for Chromium that adds some support for how GYP
 # is invoked by Chromium beyond what can be done in the gclient hooks.
 
 import glob
@@ skipping 185 matching lines @@
   ]
   for i in remap_cases:
     if i[0] in vars_dict and vars_dict[i[0]] == i[1]:
       gn_args += ' ' + i[2]
 
   # These string arguments get passed directly as GN strings.
   for v in ['android_src', 'windows_sdk_path']:
     if v in vars_dict:
       gn_args += ' ' + v + '=' + EscapeStringForGN(vars_dict[v])
 
+  # gomadir is renamed goma_dir in the GN build.
+  if 'gomadir' in vars_dict:
+    gn_args += ' goma_dir="%s"' % vars_dict['gomadir']
+
   # These arguments get passed directly as integers (avoiding the quoting and
   # escaping of the string ones above).
   for v in ['arm_version']:
     if v in vars_dict:
       gn_args += ' %s=%s' % (v, vars_dict[v])
 
   # Some other flags come from GYP environment variables.
   gyp_msvs_version = os.environ.get('GYP_MSVS_VERSION', '')
   if gyp_msvs_version:
     gn_args += ' visual_studio_version=' + EscapeStringForGN(gyp_msvs_version)
@@ skipping 175 matching lines @@
   if not RunGN(supplemental_includes):
     sys.exit(1)
   args.extend(
       ['-I' + i for i in additional_include_files(supplemental_includes, args)])
 
   print 'Updating projects from gyp files...'
   sys.stdout.flush()
 
   # Off we go...
   sys.exit(gyp.main(args))