Defer OSX output stream Start() around system supend and resume.

media/audio/mac/audio_auhal_mac.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 "media/audio/mac/audio_auhal_mac.h"
 
 #include <CoreServices/CoreServices.h>
 
 #include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/mac/mac_logging.h"
+#include "base/time/time.h"
 #include "media/audio/mac/audio_manager_mac.h"
 #include "media/base/audio_pull_fifo.h"
 
 namespace media {
 
 static void ZeroBufferList(AudioBufferList* buffer_list) {
   for (size_t i = 0; i < buffer_list->mNumberBuffers; ++i) {
     memset(buffer_list->mBuffers[i].mData,
            0,
            buffer_list->mBuffers[i].mDataByteSize);
@@ skipping 118 matching lines @@
   manager_->ReleaseOutputStream(this);
 }
 
 void AUHALStream::Start(AudioSourceCallback* callback) {
   DCHECK(callback);
   if (!audio_unit_) {
     DLOG(ERROR) << "Open() has not been called successfully";
     return;
   }
 
+  // Check if we should defer Start() for http://crbug.com/160920.
+  if (manager_->ShouldDeferOutputStreamStart()) {
+    // Use a cancellable closure so that if Stop() is called before Start()
+    // actually runs, we can cancel the pending start.
+    DCHECK(deferred_start_cb_.IsCancelled());
+    deferred_start_cb_.Reset(
+        base::Bind(&AUHALStream::Start, base::Unretained(this), callback));
+    manager_->GetTaskRunner()->PostDelayedTask(
+        FROM_HERE, deferred_start_cb_.callback(), base::TimeDelta::FromSeconds(
+            AudioManagerMac::kStartDelayInSecsForPowerEvents));
+    return;
+  }
+
   stopped_ = false;
   audio_fifo_.reset();
   {
     base::AutoLock auto_lock(source_lock_);
     source_ = callback;
   }
 
   OSStatus result = AudioOutputUnitStart(audio_unit_);
   if (result == noErr)
     return;
 
   Stop();
   OSSTATUS_DLOG(ERROR, result) << "AudioOutputUnitStart() failed.";
   callback->OnError(this);
 }
 
 void AUHALStream::Stop() {
+  deferred_start_cb_.Cancel();
   if (stopped_)
     return;
 
   OSStatus result = AudioOutputUnitStop(audio_unit_);
   OSSTATUS_DLOG_IF(ERROR, result != noErr, result)
       << "AudioOutputUnitStop() failed.";
   if (result != noErr)
     source_->OnError(this);
 
   base::AutoLock auto_lock(source_lock_);
@@ skipping 350 matching lines @@
   result = AudioUnitInitialize(audio_unit_);
   if (result != noErr) {
     OSSTATUS_DLOG(ERROR, result) << "AudioUnitInitialize() failed.";
     return false;
   }
 
   return true;
 }
 
 }  // namespace media