Replace safe-bool idiom with explicit WeakPtr::operator bool()

content/renderer/media/pepper_to_video_track_adapter.cc

 // Copyright (c) 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 "content/renderer/media/pepper_to_video_track_adapter.h"
 
 #include <string>
 
 #include "base/base64.h"
 #include "base/logging.h"
@@ skipping 191 matching lines @@
   delegate_->DeliverFrame(new_frame);
 }
 
 // PpFrameWriterProxy is a helper class to make sure the user won't use
 // PpFrameWriter after it is released (IOW its owner - WebMediaStreamSource -
 // is released).
 class PpFrameWriterProxy : public FrameWriterInterface {
  public:
   explicit PpFrameWriterProxy(const base::WeakPtr<PpFrameWriter>& writer)
       : writer_(writer) {
-    DCHECK(writer_ != NULL);
+    DCHECK(writer_);
   }
 
   ~PpFrameWriterProxy() override {}
 
   void PutFrame(PPB_ImageData_Impl* image_data,
                 int64_t time_stamp_ns) override {
     writer_->PutFrame(image_data, time_stamp_ns);
   }
 
  private:
@@ skipping 44 matching lines @@
 
   stream.addTrack(MediaStreamVideoTrack::CreateVideoTrack(
       writer, constraints, MediaStreamVideoSource::ConstraintsCallback(),
       track_enabled));
 
   *frame_writer = new PpFrameWriterProxy(writer->AsWeakPtr());
   return true;
 }
 
 }  // namespace content