Add vector_math::FMUL. Replace audio_util::AdjustVolume.

media/media.gyp

Index: media/media.gyp
diff --git a/media/media.gyp b/media/media.gyp
index 6afd4f5e4bc8d62c7b92b5cd57fc6863228b011e..e77da2509573b048cb06edc2dedd00f0c11b9b46 100644
--- a/media/media.gyp
+++ b/media/media.gyp
@@ -283,8 +283,6 @@
         'base/stream_parser.h',
         'base/stream_parser_buffer.cc',
         'base/stream_parser_buffer.h',
-        'base/vector_math.cc',
-        'base/vector_math.h',
         'base/video_decoder.cc',
         'base/video_decoder.h',
         'base/video_decoder_config.cc',
@@ -551,6 +549,7 @@
             ['include', '^base/audio_bus\\.'],
             ['include', '^base/channel_layout\\.'],
             ['include', '^base/media_stub\\.cc$'],
+            ['include', '^base/vector_math\\.'],
           ],
           'link_settings': {
             'libraries': [
@@ -888,7 +887,6 @@
         'audio/audio_output_proxy_unittest.cc',
         'audio/audio_parameters_unittest.cc',
         'audio/audio_silence_detector_unittest.cc',
-        'audio/audio_util_unittest.cc',
         'audio/cross_process_notification_unittest.cc',
         'audio/fake_audio_consumer_unittest.cc',
         'audio/ios/audio_manager_ios_unittest.cc',