Reland of Switch to use SequencedTaskChecker instead of ThreadChecker where needed.

webrtc/media/media.gyp

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'includes': [ '../build/common.gypi', ],
@@ skipping 181 matching lines @@
   'conditions': [
     ['include_tests==1', {
       'targets' : [
         {
           'target_name': 'rtc_unittest_main',
           'type': 'static_library',
           'dependencies': [
             '<(DEPTH)/testing/gmock.gyp:gmock',
             '<(DEPTH)/testing/gtest.gyp:gtest',
             '<(webrtc_root)/base/base_tests.gyp:rtc_base_tests_utils',
+            '<(webrtc_root)/media/media.gyp:rtc_media',
           ],
           'direct_dependent_settings': {
             'include_dirs': [
               '<(libyuv_dir)/include',
               '<(DEPTH)/testing/gmock/include',
             ],
           },
           'conditions': [
             ['build_libyuv==1', {
               'dependencies': ['<(DEPTH)/third_party/libyuv/libyuv.gyp:libyuv',],
@@ skipping 31 matching lines @@
             'engine/fakewebrtcvideocapturemodule.h',
             'engine/fakewebrtcvideoengine.h',
             'engine/fakewebrtcvoiceengine.h',
           ],
         },  # target rtc_unittest_main
         {
           'target_name': 'rtc_media_unittests',
           'type': 'executable',
           'dependencies': [
             '<(webrtc_root)/base/base_tests.gyp:rtc_base_tests_utils',
-            '<(webrtc_root)/media/media.gyp:rtc_media',
             '<(webrtc_root)/system_wrappers/system_wrappers.gyp:metrics_default',
             '<(webrtc_root)/test/test.gyp:test_support',
             'rtc_unittest_main',
           ],
           'sources': [
             'base/codec_unittest.cc',
             'base/rtpdataengine_unittest.cc',
             'base/rtpdump_unittest.cc',
             'base/rtputils_unittest.cc',
             'base/streamparams_unittest.cc',
@@ skipping 90 matching lines @@
               'sources': [
                 'rtc_media_unittests.isolate',
               ],
             },
           ],
         }],
       ],  # conditions
     }],  # include_tests==1
   ],  # conditions
 }