Disable GN.

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 532 matching lines @@
   gn_vars_dict = GetGypVarsForGN(supplemental_includes)
 
   # Automatically turn on crosscompile support for platforms that need it.
   # (The Chrome OS build sets CC_host / CC_target which implicitly enables
   # this mode.)
   if all(('ninja' in os.environ.get('GYP_GENERATORS', ''),
           gn_vars_dict.get('OS') in ['android', 'ios'],
           'GYP_CROSSCOMPILE' not in os.environ)):
     os.environ['GYP_CROSSCOMPILE'] = '1'
 
-  if not RunGN(gn_vars_dict):
-    sys.exit(1)
+  # TODO(brettw) bug 350974 either turn back on GN or delete all of this code.
+  #if not RunGN(gn_vars_dict):
+  #  sys.exit(1)
   args.extend(
       ['-I' + i for i in additional_include_files(supplemental_includes, args)])
 
   args.extend(['-D', 'gyp_output_dir=' + GetOutputDirectory()])
 
   print 'Updating projects from gyp files...'
   sys.stdout.flush()
 
   # Off we go...
   gyp_rc = gyp.main(args)
 
   # Check for landmines (reasons to clobber the build). This must be run here,
   # rather than a separate runhooks step so that any environment modifications
   # from above are picked up.
   print 'Running build/landmines.py...'
   subprocess.check_call(
       [sys.executable, os.path.join(script_dir, 'landmines.py')])
 
   if vs2013_runtime_dll_dirs:
     x64_runtime, x86_runtime = vs2013_runtime_dll_dirs
     CopyVsRuntimeDlls(os.path.join(chrome_src, GetOutputDirectory()),
                       (x86_runtime, x64_runtime))
 
   sys.exit(gyp_rc)