Switch audio hang monitor to default-off. Enable for non-beta,stable.

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index a8c1b1f92f9ddcf4c3092a29ea7d1d551eebaf46..a68d6de4c983d19428d0ea75428828fe1dbb27d8 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -132,6 +132,7 @@
 #include "content/public/common/content_switches.h"
 #include "content/public/common/main_function_params.h"
 #include "grit/platform_locale_settings.h"
+#include "media/audio/audio_manager.h"
 #include "net/base/net_module.h"
 #include "net/cookies/cookie_monster.h"
 #include "net/http/http_network_layer.h"
@@ -666,8 +667,18 @@ void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
   // Now that field trials have been created, initializes metrics recording.
   metrics->InitializeMetricsRecordingState();
 
+  const chrome::VersionInfo::Channel channel =
+      chrome::VersionInfo::GetChannel();
+
+  // TODO(dalecurtis): Remove these checks and enable for all channels once we
+  // track down the root causes of crbug.com/422522 and crbug.com/478932.

[Nico, 2015/04/28 17:53:38]

do you want to do this only on windows then?

[DaleCurtis, 2015/04/28 18:27:09]

Not yet, I'd like more confidence given the lower user counts on dev, beta for
other platforms. We already had one googler bug pointing to a broken pulseaudio
install.

[DaleCurtis, 2015/04/28 18:27:27]

Err lower user counts on dev, not beta.

+  if (channel == chrome::VersionInfo::CHANNEL_UNKNOWN ||
+      chrome::VersionInfo::CHANNEL_CANARY || chrome::VersionInfo::CHANNEL_DEV) {
+    media::AudioManager::EnableHangMonitor();
+  }
+
   // Enable profiler instrumentation depending on the channel.
-  switch (chrome::VersionInfo::GetChannel()) {
+  switch (channel) {
     case chrome::VersionInfo::CHANNEL_UNKNOWN:
     case chrome::VersionInfo::CHANNEL_CANARY:
       tracked_objects::ScopedTracker::Enable();