Defer input stream start around suspend and resume.

media/audio/mac/audio_low_latency_input_mac.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/mac/audio_low_latency_input_mac.h"
 
 #include <CoreServices/CoreServices.h>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 256 matching lines @@
   number_of_channels_in_frame_ = GetNumberOfChannelsFromStream();
 
   return true;
 }
 
 void AUAudioInputStream::Start(AudioInputCallback* callback) {
   DCHECK(callback);
   DLOG_IF(ERROR, !audio_unit_) << "Open() has not been called successfully";
   if (started_ || !audio_unit_)
     return;
+
+  // Check if we should defer Start() for http://crbug.com/160920.
+  if (manager_->ShouldDeferStreamStart()) {
+    // 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(
+        &AUAudioInputStream::Start, base::Unretained(this), callback));
+    manager_->GetTaskRunner()->PostDelayedTask(
+        FROM_HERE,
+        deferred_start_cb_.callback(),
+        base::TimeDelta::FromSeconds(
+            AudioManagerMac::kStartDelayInSecsForPowerEvents));
+    return;
+  }
+
   sink_ = callback;
   StartAgc();
   OSStatus result = AudioOutputUnitStart(audio_unit_);
   if (result == noErr) {
     started_ = true;
   }
   OSSTATUS_DLOG_IF(ERROR, result != noErr, result)
       << "Failed to start acquiring data";
 }
 
@@ skipping 368 matching lines @@
     kAudioDevicePropertyScopeInput,
     static_cast<UInt32>(channel)
   };
   OSStatus result = AudioObjectIsPropertySettable(input_device_id_,
                                                   &property_address,
                                                   &is_settable);
   return (result == noErr) ? is_settable : false;
 }
 
 }  // namespace media