Temporarily disabling new gUM test on Mac since it's broken.

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 616 matching lines @@
   ASSERT_TRUE(recorder.StartRecording(recording_time, recording, false, true));
 
   NegotiateCall(left_tab, right_tab);
 
   ASSERT_TRUE(recorder.WaitForRecordingToEnd());
   DVLOG(0) << "Done recording to " << recording.value() << std::endl;
 
   HangUp(left_tab);
 }
 
+#if defined(OS_MACOSX)
+// Broken on Mac for some reason: http://crbug.com/446859.
+#define MAYBE_MANUAL_TestCallQualityWithAudioFromFakeDevice \
+    DISABLED_MANUAL_TestCallQualityWithAudioFromFakeDevice
+#else
+#define MAYBE_MANUAL_TestCallQualityWithAudioFromFakeDevice \
+    MANUAL_TestCallQualityWithAudioFromFakeDevice
+#endif
+
 IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcAudioQualityBrowserTest,
-                       MANUAL_TestCallQualityWithAudioFromFakeDevice) {
+                       MAYBE_MANUAL_TestCallQualityWithAudioFromFakeDevice) {
   if (OnWinXp() || OnWin8()) {
     // http://crbug.com/379798.
     LOG(ERROR) << "This test is not implemented for Windows XP/Win8.";
     return;
   }
 
   base::FilePath reference_file =
       test::GetReferenceFilesDir().Append(kReferenceFile);
   base::FilePath recording = CreateTemporaryWaveFile();
 
@@ skipping 143 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(
       kAgcTestReferenceFile, kAudioCallWithoutAudioProcessing, "_no_agc"));
 }