MidiScheduler binds to task runner of constructing thread

media/midi/midi_manager_android.cc

Index: media/midi/midi_manager_android.cc
diff --git a/media/midi/midi_manager_android.cc b/media/midi/midi_manager_android.cc
index 54fe91514c903f3f1189be369fa316f017589d3f..25966260b01fd2ec0b16f7691bf89006dbf74ac2 100644
--- a/media/midi/midi_manager_android.cc
+++ b/media/midi/midi_manager_android.cc
@@ -35,7 +35,10 @@ MidiManager* MidiManager::Create() {
 
 MidiManagerAndroid::MidiManagerAndroid() {}
 
-MidiManagerAndroid::~MidiManagerAndroid() {}
+MidiManagerAndroid::~MidiManagerAndroid() {
+  base::AutoLock auto_lock(scheduler_lock_);
+  CHECK(!scheduler_);
+}
 
 void MidiManagerAndroid::StartInitialization() {
   JNIEnv* env = base::android::AttachCurrentThread();
@@ -43,10 +46,21 @@ void MidiManagerAndroid::StartInitialization() {
   uintptr_t pointer = reinterpret_cast<uintptr_t>(this);
   raw_manager_.Reset(Java_MidiManagerAndroid_create(
       env, base::android::GetApplicationContext(), pointer));
-  scheduler_.reset(new MidiScheduler(this));
+
+  {
+    base::AutoLock auto_lock(scheduler_lock_);
+    scheduler_.reset(new MidiScheduler(this));
+  }
+
   Java_MidiManagerAndroid_initialize(env, raw_manager_);
 }
 
+void MidiManagerAndroid::Finalize() {
+  // Destruct MidiScheduler on Chrome_IOThread.
+  base::AutoLock auto_lock(scheduler_lock_);
+  scheduler_.reset();
+}
+
 void MidiManagerAndroid::DispatchSendMidiData(MidiManagerClient* client,
                                               uint32_t port_index,
                                               const std::vector<uint8_t>& data,