Fix ChromiumOS build (it still has circular dependencies).

build/gyp_chromium

 #!/usr/bin/python
 
 # Copyright (c) 2009 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 61 matching lines @@
 
   args.extend(['-I' + i for i in additional_include_files(args)])
 
   # There shouldn't be a circular dependency relationship between .gyp files,
   # but in Chromium's .gyp files, on non-Mac platforms, circular relationships
   # currently exist.  The check for circular dependencies is currently
   # bypassed on other platforms, but is left enabled on the Mac, where a
   # violation of the rule causes Xcode to misbehave badly.
   # TODO(mark): Find and kill remaining circular dependencies, and remove this
   # option.  http://crbug.com/35878.
-  if sys.platform not in ('darwin', 'linux2'):
+  # TODO(tc): Fix circular dependencies in ChromiumOS then add linux2 to the
+  # list.
+  if sys.platform not in ('darwin',):
     args.append('--no-circular-check')
 
   # If CHROMIUM_GYP_SYNTAX_CHECK is set to 1, it will invoke gyp with --check
   # to enfore syntax checking.
   syntax_check = os.environ.get('CHROMIUM_GYP_SYNTAX_CHECK')
   if syntax_check and int(syntax_check):
     args.append('--check')
 
   print 'Updating projects from gyp files...'
   sys.stdout.flush()
 
   # Off we go...
   sys.exit(gyp.main(args))