Cleanup AudioDeviceThread to reduce locking and unused features.

media/audio/audio_input_device.cc

Index: media/audio/audio_input_device.cc
diff --git a/media/audio/audio_input_device.cc b/media/audio/audio_input_device.cc
index fc6b39285ad363aeb2e7591eacfcd77b8d97bfbb..71518d79951b35a678dc654afb3c70072b289399 100644
--- a/media/audio/audio_input_device.cc
+++ b/media/audio/audio_input_device.cc
@@ -94,7 +94,7 @@ void AudioInputDevice::Stop() {
 
   {
     base::AutoLock auto_lock(audio_thread_lock_);
-    audio_thread_.Stop(base::MessageLoop::current());
+    audio_thread_.reset();
     stopping_hack_ = true;
   }
 
@@ -143,11 +143,12 @@ void AudioInputDevice::OnStreamCreated(
   if (stopping_hack_)
     return;
 
-  DCHECK(audio_thread_.IsStopped());
+  DCHECK(!audio_callback_);
+  DCHECK(!audio_thread_);
   audio_callback_.reset(new AudioInputDevice::AudioThreadCallback(
       audio_parameters_, handle, length, total_segments, callback_));
-  audio_thread_.Start(
-      audio_callback_.get(), socket_handle, "AudioInputDevice", true);
+  audio_thread_.reset(new AudioDeviceThread(audio_callback_.get(),
+                                            socket_handle, "AudioInputDevice"));
 
   state_ = RECORDING;
   ipc_->RecordStream();
@@ -182,9 +183,13 @@ void AudioInputDevice::OnStateChanged(
       // TODO(tommi): Add an explicit contract for clearing the callback
       // object.  Possibly require calling Initialize again or provide
       // a callback object via Start() and clear it in Stop().
-      if (!audio_thread_.IsStopped())
-        callback_->OnCaptureError(
-            "AudioInputDevice::OnStateChanged - audio thread still running");
+      {
+        base::AutoLock auto_lock_(audio_thread_lock_);

[tommi (sloooow) - chröme, 2016/06/16 22:19:22]

auto_lock

+        if (audio_thread_) {
+          callback_->OnCaptureError(
+              "AudioInputDevice::OnStateChanged - audio thread still running");
+        }
+      }
       break;
     default:
       NOTREACHED();
@@ -198,11 +203,7 @@ void AudioInputDevice::OnIPCClosed() {
   ipc_.reset();
 }
 
-AudioInputDevice::~AudioInputDevice() {
-  // TODO(henrika): The current design requires that the user calls
-  // Stop before deleting this class.
-  DCHECK(audio_thread_.IsStopped());
-}
+AudioInputDevice::~AudioInputDevice() {}
 
 void AudioInputDevice::StartUpOnIOThread() {
   DCHECK(task_runner()->BelongsToCurrentThread());
@@ -241,7 +242,7 @@ void AudioInputDevice::ShutDownOnIOThread() {
   // and can't not rely on the main thread existing either.
   base::AutoLock auto_lock_(audio_thread_lock_);
   base::ThreadRestrictions::ScopedAllowIO allow_io;
-  audio_thread_.Stop(NULL);
+  audio_thread_.reset();
   audio_callback_.reset();
   stopping_hack_ = false;
 }