Disable tcmalloc on nvidia GPU bots to work around hangs.

build/masters/master.chromium.gpu/master.cfg

 # 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.
 
 from buildbot.changes import svnpoller
 from buildbot.scheduler import Dependent
 from buildbot.scheduler import Scheduler
 
 from master import build_utils
 from master import master_config
@@ skipping 251 matching lines @@
     target='Release',
     slave_type='BuilderTester',
     options=['chromium_gpu_builder'],
     tests=full_test_suite,
     factory_properties={
       'test_results_server': 'test-results.appspot.com',
       'perf_id': 'gpu-linux-release-nvidia',
       'show_perf_results': True,
       'generate_gtest_json': True,
       'gclient_env': {
-          'GYP_DEFINES': 'fastbuild=1 internal_gles2_conform_tests=1',
+        # tcmalloc disabled because of hangs: http://crbug.com/177218 .
+        'GYP_DEFINES': 'fastbuild=1 internal_gles2_conform_tests=1 '
+                       'linux_use_tcmalloc=0',
       },
     })
 
 f_linux_nvidia_dbg = F_LINUX(
     target='Debug',
     slave_type='BuilderTester',
     options=['chromium_gpu_debug_builder'],
     tests=debug_test_suite,
     factory_properties={
       'test_results_server': 'test-results.appspot.com',
       'generate_gtest_json': True,
       'gclient_env': {
-        'GYP_DEFINES': 'fastbuild=1 internal_gles2_conform_tests=1',
+        # tcmalloc disabled because of hangs: http://crbug.com/177218 .
+        'GYP_DEFINES': 'fastbuild=1 internal_gles2_conform_tests=1 '
+                       'linux_use_tcmalloc=0',
       },
     })
 
 f_linux_ati_rel = F_LINUX(
     target='Release',
     slave_type='BuilderTester',
     options=['chromium_gpu_builder'],
     tests=full_test_suite,
     factory_properties={
       'perf_id': 'gpu-fyi-linux-release-ati',
@@ skipping 93 matching lines @@
 # Adds common status and tools to this master.
 master_utils.AutoSetupMaster(c, ActiveMaster,
     public_html='../master.chromium/public_html',
     templates=['../master.chromium/templates'],
     enable_http_status_push=ActiveMaster.is_production_host)
 
 ####### PROJECT IDENTITY
 
 # Buildbot master url:
 c['buildbotURL'] = 'http://build.chromium.org/p/chromium.gpu/'