android: Set gcc_version in build/common.gypi instead of in envsetup.

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 119 matching lines @@
   Based on a subset of the GYP variables that have been rewritten a bit."""
 
   vars_dict = GetGypVarsForGN(supplemental_files)
   gn_args = ''
 
   # Note: These are the additional flags passed to various builds by builders
   # on the main waterfall. We'll probably need to add these at some point:
   #   mac_strip_release=1         http://crbug.com/330301
   #   linux_dump_symbols=0        http://crbug.com/330300
   #   host_os=linux  Probably can skip, GN knows the host OS.
-  #   gcc_version=46  Hopefully we can skip this and fix whatever uses it.
   #   order_text_section=<path>   http://crbug.com/330299
   #   chromium_win_pch=0          http://crbug.com/297678
   #   clang_use_chrome_plugins=1  http://crbug.com/330298
   #   chromium_ios_signing=0      http://crbug.com/330302
   #   linux_use_tcmalloc=0        http://crbug.com/330303
   #   release_extra_flags=...     http://crbug.com/330305
 
   # These tuples of (key, value, gn_arg_string) use the gn_arg_string for
   # gn when the key is set to the given value in the GYP arguments.
   remap_cases = [
@@ skipping 225 matching lines @@
   # 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))