Turn ThreadPriority enum into an enum class.

content/renderer/media/webrtc_local_audio_track_unittest.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 "base/synchronization/waitable_event.h"
 #include "base/test/test_timeouts.h"
 #include "content/public/renderer/media_stream_audio_sink.h"
 #include "content/renderer/media/media_stream_audio_source.h"
 #include "content/renderer/media/mock_media_constraint_factory.h"
 #include "content/renderer/media/webrtc/webrtc_local_audio_track_adapter.h"
@@ skipping 48 matching lines @@
       audio_bus_->Zero();
       callback->Capture(audio_bus_.get(), 0, 0, false);
 
       // Sleep 1ms to yield the resource for the main thread.
       base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(1));
     }
   }
 
   void Start() {
     base::PlatformThread::CreateWithPriority(
-        0, this, &thread_, base::kThreadPriority_RealtimeAudio);
+        0, this, &thread_, base::ThreadPriority::REALTIME_AUDIO);
     CHECK(!thread_.is_null());
   }
 
   void Stop() {
     closure_.Signal();
     base::PlatformThread::Join(thread_);
     thread_ = base::PlatformThreadHandle();
   }
 
  private:
@@ skipping 427 matching lines @@
   // Stopping the new source will stop the second track.
   EXPECT_CALL(*source.get(), OnStop()).Times(1);
   capturer->Stop();
 
   // Even though this test don't use |capturer_source_| it will be stopped
   // during teardown of the test harness.
   EXPECT_CALL(*capturer_source_.get(), OnStop());
 }
 
 }  // namespace content