Add use_allocator instead of linux_use_tcmalloc to switch the allocator.

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 174 matching lines @@
   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.
   #   order_text_section=<path>   http://crbug.com/330299
   #   chromium_win_pch=0          http://crbug.com/297678
   #   chromium_ios_signing=0      http://crbug.com/330302
-  #   linux_use_tcmalloc=0        http://crbug.com/330303
+  #   use_allocator=tcmalloc      http://crbug.com/330303, 345554
   #   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 = [
       ('android_webview_build', '1', 'is_android_webview_build=true'),
       ('branding', 'Chrome', 'is_chrome_branded=true'),
       ('build_for_tool', 'drmemory', 'disable_iterator_debugging=true'),
       ('build_for_tool', 'tsan', 'disable_iterator_debugging=true'),
       ('buildtype', 'Official', 'is_official_build=true'),
@@ skipping 350 matching lines @@
   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)