Disable low latency audio under remote desktop sessions.

media/audio/win/core_audio_util_win.cc

 // Copyright (c) 2012 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 "media/audio/win/core_audio_util_win.h"
 
 #include <audioclient.h>
 #include <devicetopology.h>
 #include <functiondiscoverykeys_devpkey.h>
 
@@ skipping 152 matching lines @@
     DVLOG(1) << "Forcing usage of Windows WaveXxx APIs";
     return false;
   }
 
   // Microsoft does not plan to make the Core Audio APIs available for use
   // with earlier versions of Windows, including Microsoft Windows Server 2003,
   // Windows XP, Windows Millennium Edition, Windows 2000, and Windows 98.
   if (base::win::GetVersion() < base::win::VERSION_VISTA)
     return false;
 
+  // Don't use CoreAudio when a remote desktop session is present; several users
+  // report only WaveAudio working for them and crash reports show hangs when
+  // calling into the OS for CoreAudio API calls. See http://crbug.com/422522
+  // and http://crbug.com/180591.
+  //
+  // Note: It's possible that a user will connect a remote desktop session after
+  // this check has been done. In practice this shouldn't be the dominant case
+  // though and CoreAudio does work for many users.
+  if (GetSystemMetrics(SM_REMOTESESSION))

[henrika (OOO until Aug 14), 2015/04/05 14:41:08]

This is the only detection method I could find as well. I have no better idea.

+    return false;
+
   // The audio core APIs are implemented in the Mmdevapi.dll and Audioses.dll
   // system components.
   // Dependency Walker shows that it is enough to verify possibility to load
   // the Audioses DLL since it depends on Mmdevapi.dll.
   // See http://crbug.com/166397 why this extra step is required to guarantee
   // Core Audio support.
   static bool g_audioses_dll_available = LoadAudiosesDll();
   if (!g_audioses_dll_available)
     return false;
 
@@ skipping 665 matching lines @@
     return false;
 
   // Using the AUDCLNT_BUFFERFLAGS_SILENT flag eliminates the need to
   // explicitly write silence data to the rendering buffer.
   DVLOG(2) << "filling up " << num_frames_to_fill << " frames with silence";
   return SUCCEEDED(render_client->ReleaseBuffer(num_frames_to_fill,
                                                 AUDCLNT_BUFFERFLAGS_SILENT));
 }
 
 }  // namespace media