Moved the fake input stream's processing onto the audio worker thread.

chrome/browser/media/chrome_webrtc_audio_quality_browsertest.cc

 // Copyright 2013 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.
 
 #include <ctime>
 
 #include "base/command_line.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 248 matching lines @@
   if (!base::GetAppOutput(command_line, &result)) {
     LOG(ERROR) << "Failed to set source volume: output was " << result;
     return false;
   }
 #elif defined(OS_MACOSX)
   base::CommandLine command_line(
       base::FilePath(FILE_PATH_LITERAL("osascript")));
   command_line.AppendArg("-e");
   command_line.AppendArg("set volume input volume 100");
   command_line.AppendArg("-e");
-  command_line.AppendArg("set volume output volume 100");
+  command_line.AppendArg("set volume output volume 85");
 
   std::string result;
   if (!base::GetAppOutput(command_line, &result)) {
     LOG(ERROR) << "Failed to set source volume: output was " << result;
     return false;
   }
 #else
   // Just force the volume of, say the first 5 devices. A machine will rarely
   // have more input sources than that. This is way easier than finding the
   // input device we happen to be using.
@@ skipping 494 matching lines @@
 #endif
 
 // Since the AGC is off here there should be no gain at all.
 IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcAudioQualityBrowserTest,
                        MAYBE_MANUAL_TestAutoGainIsOffWithAudioProcessingOff) {
   const char* kAudioCallWithoutAudioProcessing =
       "{audio: { mandatory: { echoCancellation: false } } }";
   ASSERT_NO_FATAL_FAILURE(TestAutoGainControl(
       kReferenceFile, kAudioCallWithoutAudioProcessing, "_no_agc"));
 }