Windows bots build and use OSMesa...

build/all.gyp

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'All',
       'type': 'none',
       'xcode_create_dependents_test_runner': 1,
@@ skipping 216 matching lines @@
             # 1) not be the case. OR.
             # 2) be expressed in the ui tests dependencies.
             '../webkit/webkit.gyp:test_shell_common',
             'temp_gyp/googleurl.gyp:googleurl_unittests',
             '../chrome_frame/chrome_frame.gyp:chrome_frame_net_tests',
             '../chrome_frame/chrome_frame.gyp:chrome_frame_perftests',
             '../chrome_frame/chrome_frame.gyp:chrome_frame_reliability_tests',
             '../chrome_frame/chrome_frame.gyp:chrome_frame_tests',
             '../chrome_frame/chrome_frame.gyp:chrome_frame_unittests',
             '../chrome_frame/chrome_frame.gyp:npchrome_frame',
+            # Only build OSMesa on buildbots. It builds a software GL renderer
+            # that can be used where native GL is not available.
+            '../third_party/mesa/mesa.gyp:osmesa',
           ],
         },
         {
           'target_name': 'chromium_builder_dbg_tsan_win',
           'type': 'none',
           'dependencies': [
             '../app/app.gyp:app_unittests',
             '../base/base.gyp:base_unittests',
             'temp_gyp/googleurl.gyp:googleurl_unittests',
             '../net/net.gyp:net_unittests',
@@ skipping 44 matching lines @@
       ],  # targets
     }], # "chromeos==1"
   ], # conditions
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: