cc: Drop ContextProvider references on the impl thread before quitting

cc/cc_tests.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
     'cc_unit_tests_source_files': [
       'animation/animation_unittest.cc',
       'animation/keyframed_animation_curve_unittest.cc',
@@ skipping 41 matching lines @@
       'resources/picture_layer_tiling_unittest.cc',
       'resources/picture_pile_impl_unittest.cc',
       'resources/picture_pile_unittest.cc',
       'resources/picture_unittest.cc',
       'resources/prioritized_resource_unittest.cc',
       'resources/prioritized_tile_set_unittest.cc',
       'resources/raster_worker_pool_unittest.cc',
       'resources/resource_provider_unittest.cc',
       'resources/resource_update_controller_unittest.cc',
       'resources/scoped_resource_unittest.cc',
+      'resources/texture_mailbox_deleter_unittest.cc',
       'resources/tile_manager_unittest.cc',
       'resources/tile_priority_unittest.cc',
       'resources/video_resource_updater_unittest.cc',
       'resources/worker_pool_unittest.cc',
       'scheduler/delay_based_time_source_unittest.cc',
       'scheduler/frame_rate_controller_unittest.cc',
       'scheduler/rolling_time_delta_history_unittest.cc',
       'scheduler/scheduler_state_machine_unittest.cc',
       'scheduler/scheduler_unittest.cc',
       'scheduler/texture_uploader_unittest.cc',
@@ skipping 272 matching lines @@
               'test_suite_name': 'cc_perftests',
               'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)cc_perftests<(SHARED_LIB_SUFFIX)',
             },
             'includes': [ '../build/apk_test.gypi' ],
           },
         ],
       }
     ]
   ],
 }