Revert of Enabling audio quality test on mac. (patchset #1 id:1 of...

Revert of Enabling audio quality test on mac. (patchset #1 id:1 of https://codereview.chromium.org/599103006/)

Reason for revert:
There is one stubborn bot that is unreachable from VNC; reverting until we can sort that out.

Original issue's description:
> Enabling audio quality test on mac.
>
> Note: will land on Monday; need to watch bots so that they execute the
> test right.
>
> TBR=vrk@chromium.org
> BUG=418034
>
> Committed: https://crrev.com/c4e4aaaf43c0da2a01c0f32be737dcbbd5f13e92
> Cr-Commit-Position: refs/heads/master@{#297166}

TBR=vrk@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=418034

Review URL: https://codereview.chromium.org/613833002

Cr-Commit-Position: refs/heads/master@{#297257}

chrome/browser/media/chrome_webrtc_audio_quality_browsertest.cc

@@ -378,10 +378,10 @@ bool RunPesq(const base::FilePath& reference_file,
   return true;
 }
 
-#if defined(OS_LINUX) || defined(OS_WIN) || defined(OS_MACOSX)
+#if defined(OS_LINUX) || defined(OS_WIN)
+// Only implemented on Linux and Windows for now.
 #define MAYBE_MANUAL_TestAudioQuality MANUAL_TestAudioQuality
 #else
-// Not implemented on Android, ChromeOS etc.
 #define MAYBE_MANUAL_TestAudioQuality DISABLED_MANUAL_TestAudioQuality
 #endif