[PPAPI][MediaStream] Add browser tests for MediaStreamAudioTrack

ppapi/ppapi_sources.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.
 
 {
   'variables': {
     'c_source_files': [
       'c/pp_array_output.h',
       'c/pp_bool.h',
       'c/pp_completion_callback.h',
@@ skipping 437 matching lines @@
       'tests/test_host_resolver_private.cc',
       'tests/test_host_resolver_private.h',
       'tests/test_host_resolver_private_disallowed.cc',
       'tests/test_host_resolver_private_disallowed.h',
       'tests/test_image_data.cc',
       'tests/test_image_data.h',
       'tests/test_ime_input_event.cc',
       'tests/test_ime_input_event.h',
       'tests/test_input_event.cc',
       'tests/test_input_event.h',
+      'tests/test_media_stream_audio_track.cc',
+      'tests/test_media_stream_audio_track.h',
       'tests/test_media_stream_video_track.cc',
       'tests/test_media_stream_video_track.h',
       'tests/test_memory.cc',
       'tests/test_memory.h',
       'tests/test_message_loop.cc',
       'tests/test_message_loop.h',
       'tests/test_mouse_cursor.cc',
       'tests/test_mouse_cursor.h',
       'tests/test_mouse_lock.cc',
       'tests/test_mouse_lock.h',
@@ skipping 117 matching lines @@
       'tests/test_x509_certificate_private.h',
 
       # Deprecated test cases.
       'tests/test_instance_deprecated.cc',
       'tests/test_instance_deprecated.h',
       'tests/test_var_deprecated.cc',
       'tests/test_var_deprecated.h',
     ],
   },
 }