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

media/audio/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/linux/pkg_config.gni")
 import("//media/media_options.gni")
 
 # When libpulse is not directly linked, use stubs to allow for dlopening of the
 # binary.
 if (!link_pulseaudio) {
@@ skipping 230 matching lines @@
       libs += [ "dl" ]
       deps += [ ":pulse_generate_stubs" ]
       sources += get_target_outputs(":pulse_generate_stubs")
     }
   }
 }
 
 source_set("test_support") {
   testonly = true
   sources = [
+    "audio_unittest_util.cc",
+    "audio_unittest_util.h",
     "mock_audio_manager.cc",
     "mock_audio_manager.h",
     "mock_audio_source_callback.cc",
     "mock_audio_source_callback.h",
     "test_audio_input_controller_factory.cc",
     "test_audio_input_controller_factory.h",
   ]
   deps = [
     "//testing/gmock",
   ]
@@ skipping 64 matching lines @@
     ]
   }
 
   if (use_alsa) {
     sources += [
       "alsa/alsa_output_unittest.cc",
       "audio_low_latency_input_output_unittest.cc",
     ]
   }
 }