Add flag --require-audio-hardware-for-testing.

media/media.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,
     # Override to dynamically link the cras (ChromeOS audio) library.
     'use_cras%': 0,
     # Option e.g. for Linux distributions to link pulseaudio directly
@@ skipping 1443 matching lines @@
       'type': 'static_library',
       'dependencies': [
         'media',
         'shared_memory_support',
         '../base/base.gyp:base',
         '../skia/skia.gyp:skia',
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
       ],
       'sources': [
+        'audio/audio_unittest_util.cc',
+        'audio/audio_unittest_util.h',
         'audio/mock_audio_manager.cc',
         'audio/mock_audio_manager.h',
         'audio/mock_audio_source_callback.cc',
         'audio/mock_audio_source_callback.h',
         'audio/test_audio_input_controller_factory.cc',
         'audio/test_audio_input_controller_factory.h',
         'base/fake_audio_render_callback.cc',
         'base/fake_audio_render_callback.h',
         'base/fake_audio_renderer_sink.cc',
         'base/fake_audio_renderer_sink.h',
@@ skipping 450 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'media_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }