Convert media constants to constexpr.

content/renderer/media/webrtc/media_stream_remote_video_source.cc

 // Copyright 2014 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 "content/renderer/media/webrtc/media_stream_remote_video_source.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 62 matching lines @@
   // WebRTC Chromium timestamp diff
   const base::TimeDelta time_diff_;
 };
 
 MediaStreamRemoteVideoSource::RemoteVideoSourceDelegate::
     RemoteVideoSourceDelegate(
         scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
         const VideoCaptureDeliverFrameCB& new_frame_callback)
     : io_task_runner_(io_task_runner),
       frame_callback_(new_frame_callback),
-      start_timestamp_(media::kNoTimestamp()),
+      start_timestamp_(media::kNoTimestamp),
       // TODO(qiangchen): There can be two differences between clocks: 1)
       // the offset, 2) the rate (i.e., one clock runs faster than the other).
       // See http://crbug/516700
       time_diff_(base::TimeTicks::Now() - base::TimeTicks() -
                  base::TimeDelta::FromMicroseconds(rtc::TimeMicros())) {}
 
 MediaStreamRemoteVideoSource::
 RemoteVideoSourceDelegate::~RemoteVideoSourceDelegate() {
 }
 
 namespace {
 void DoNothing(const scoped_refptr<rtc::RefCountInterface>& ref) {}
 }  // anonymous
 
 void MediaStreamRemoteVideoSource::RemoteVideoSourceDelegate::OnFrame(
     const cricket::VideoFrame& incoming_frame) {
   const base::TimeDelta incoming_timestamp = base::TimeDelta::FromMicroseconds(
       incoming_frame.GetTimeStamp() / rtc::kNumNanosecsPerMicrosec);
   const base::TimeTicks render_time =
       base::TimeTicks() + incoming_timestamp + time_diff_;
 
   TRACE_EVENT1("webrtc", "RemoteVideoSourceDelegate::RenderFrame",
                "Ideal Render Instant", render_time.ToInternalValue());
 
-  CHECK_NE(media::kNoTimestamp(), incoming_timestamp);
-  if (start_timestamp_ == media::kNoTimestamp())
+  CHECK_NE(media::kNoTimestamp, incoming_timestamp);
+  if (start_timestamp_ == media::kNoTimestamp)
     start_timestamp_ = incoming_timestamp;
   const base::TimeDelta elapsed_timestamp =
       incoming_timestamp - start_timestamp_;
 
   scoped_refptr<media::VideoFrame> video_frame;
   scoped_refptr<webrtc::VideoFrameBuffer> buffer(
       incoming_frame.video_frame_buffer());
 
   if (buffer->native_handle() != NULL) {
     video_frame = static_cast<media::VideoFrame*>(buffer->native_handle());
@@ skipping 122 matching lines @@
     case webrtc::MediaStreamTrackInterface::kEnded:
       SetReadyState(blink::WebMediaStreamSource::ReadyStateEnded);
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 }  // namespace content