Enable renderer side mixing behind a flag.

content/content_tests.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'test_support_content',
       'type': 'static_library',
       'defines!': ['CONTENT_IMPLEMENTATION'],
@@ skipping 308 matching lines @@
         'common/sandbox_mac_unittest_helper.mm',
         'common/sandbox_mac_system_access_unittest.mm',
         'gpu/gpu_info_collector_unittest.cc',
         'gpu/gpu_info_collector_unittest_win.cc',
         'renderer/active_notification_tracker_unittest.cc',
         'renderer/android/email_detector_unittest.cc',
         'renderer/android/phone_number_detector_unittest.cc',
         'renderer/gpu/input_event_filter_unittest.cc',
         'renderer/media/audio_device_unittest.cc',
         'renderer/media/audio_message_filter_unittest.cc',
+        'renderer/media/audio_renderer_mixer_manager_unittest.cc',
         'renderer/media/capture_video_decoder_unittest.cc',
         'renderer/media/video_capture_impl_unittest.cc',
         'renderer/media/video_capture_message_filter_unittest.cc',
         'renderer/paint_aggregator_unittest.cc',
         'renderer/pepper/pepper_broker_impl_unittest.cc',
         'renderer/v8_value_converter_impl_unittest.cc',
         'test/gpu/gpu_test_config_unittest.cc',
         'test/gpu/gpu_test_expectations_parser_unittest.cc',
         'test/run_all_unittests.cc',
         '../webkit/appcache/manifest_parser_unittest.cc',
@@ skipping 344 matching lines @@
               '<(PRODUCT_DIR)/lib.java/chromium_base.jar',
               '<(PRODUCT_DIR)/lib.java/chromium_content.jar',
             ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }