base: Support setting thread priorities generically.

media/audio/audio_device_thread.cc

Index: media/audio/audio_device_thread.cc
diff --git a/media/audio/audio_device_thread.cc b/media/audio/audio_device_thread.cc
index 7583c9ed91218d73a21c920ee2463e7fbe421858..fa644834940975eb4bff17cd97e934851d2a98cd 100644
--- a/media/audio/audio_device_thread.cc
+++ b/media/audio/audio_device_thread.cc
@@ -101,12 +101,12 @@ AudioDeviceThread::Thread::Thread(AudioDeviceThread::Callback* callback,
 }
 
 AudioDeviceThread::Thread::~Thread() {
-  DCHECK_EQ(thread_, base::kNullThreadHandle) << "Stop wasn't called";
+  DCHECK(thread_ == base::kNullThreadHandle);
 }
 
 void AudioDeviceThread::Thread::Start() {
   base::AutoLock auto_lock(callback_lock_);
-  DCHECK_EQ(thread_, base::kNullThreadHandle);
+  DCHECK(thread_ == base::kNullThreadHandle);
   // This reference will be released when the thread exists.
   AddRef();