Attempt to fix audio wedges by restarting all streams.

media/audio/audio_output_controller.cc

Index: media/audio/audio_output_controller.cc
diff --git a/media/audio/audio_output_controller.cc b/media/audio/audio_output_controller.cc
index af1a122865d9eda188660103f856b665d1a1290d..fc515f1523f99ac52068a94c9765e15463c9bedf 100644
--- a/media/audio/audio_output_controller.cc
+++ b/media/audio/audio_output_controller.cc
@@ -215,7 +215,7 @@ void AudioOutputController::DoPlay() {
   // invalidate the previous timer.
   wedge_timer_.reset(new base::OneShotTimer<AudioOutputController>());
   wedge_timer_->Start(
-      FROM_HERE, TimeDelta::FromSeconds(5), this,
+      FROM_HERE, TimeDelta::FromSeconds(1), this,

[scherkus (not reviewing), 2013/12/02 21:49:37]

FYI changing this value will impact the results of
Media.AudioOutputControllerPlaybackStartupSuccess, which means it's no longer
valid to view this histogram across all versions

[DaleCurtis, 2013/12/02 22:23:59]

For safety I'm going to revert this change.  Since most sounds are hung on
resume, usually due to background activation (i.e. without user interaction),
the 5 second timeout might be fine.  My hunch is users probably aren't aware
their audio is hung within that 5 second window.

       &AudioOutputController::WedgeCheck);
 
   handler_->OnPlaying();
@@ -475,8 +475,15 @@ void AudioOutputController::WedgeCheck() {
 
   // If we should be playing and we haven't, that's a wedge.
   if (state_ == kPlaying) {
-    UMA_HISTOGRAM_BOOLEAN("Media.AudioOutputControllerPlaybackStartupSuccess",
-                          base::AtomicRefCountIsOne(&on_more_io_data_called_));
+    const bool playback_success =
+        base::AtomicRefCountIsOne(&on_more_io_data_called_);
+
+    UMA_HISTOGRAM_BOOLEAN(
+        "Media.AudioOutputControllerPlaybackStartupSuccess", playback_success);
+
+    // Let the AudioManager try and fix it.
+    if (!playback_success)
+      audio_manager_->FixWedgedAudio();

[scherkus (not reviewing), 2013/12/02 21:49:37]

Hmm I was under the impression we'd be landing a Mac-specific workaround. Do we
really want to land this workaround for all OSes when we don't really know if a
problem exists (and for that matter one that we can reproduce?)

For example, we only know that closing all streams fixes the problem on Mac.
That may not be true on other OSes.

Options include:
  1) #ifdef'ing just this bit of code
  2) #ifdef'ing all the code
  3) renaming / shuffling things, such as:
    - Rename FixWedgedAudio() to something like DetectedWedgedAudio()
    - Make the base class implementation do nothing
    - Have the Mac backend implement the workaround

My preference is for something like (3) as it limits the workaround to the
platform that needs it w/o sprinkling #ifdefs around

[DaleCurtis, 2013/12/02 22:23:59]

(3) is fine, I wanted to get the idea sanitized before I made it more specific.

[DaleCurtis, 2013/12/02 22:52:08]

Actually 3 wasn't possible since the fix requires private details of
AudioManagerBase to implement.  It's not so bad though, only a single #ifdef is
necessary.

   }
 }