Replace ASSERT with DCHECK per chromium style guide.

content/renderer/media/video_source_handler.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/video_source_handler.h"
 
 #include <string>
 
 #include "base/logging.h"
 #include "content/renderer/media/media_stream_dependency_factory.h"
@@ skipping 44 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(PpFrameReceiver);
 };
 
 VideoSourceHandler::VideoSourceHandler(
     MediaStreamRegistryInterface* registry)
     : registry_(registry) {
 }
 
 VideoSourceHandler::~VideoSourceHandler() {
   // All the opened readers should have been closed by now.
-  ASSERT(reader_to_receiver_.empty());
+  DCHECK(reader_to_receiver_.empty());
 }
 
 bool VideoSourceHandler::Open(const std::string& url,
                               FrameReaderInterface* reader) {
   scoped_refptr<webrtc::VideoSourceInterface> source = GetFirstVideoSource(url);
   if (!source.get()) {
     return false;
   }
   PpFrameReceiver* receiver = new PpFrameReceiver();
   receiver->SetReader(reader);
   source->AddSink(receiver);
   reader_to_receiver_[reader] = receiver;
   return true;
 }
 
 bool VideoSourceHandler::Close(const std::string& url,
                                FrameReaderInterface* reader) {
   scoped_refptr<webrtc::VideoSourceInterface> source = GetFirstVideoSource(url);
   if (!source.get()) {
     LOG(ERROR) << "VideoSourceHandler::Close - Failed to get the video source "
                << "from MediaStream with url: " << url;
     return false;
   }
   PpFrameReceiver* receiver =
       static_cast<PpFrameReceiver*>(GetReceiver(reader));
-  ASSERT(receiver != NULL);
+  if (!receiver) {
+    LOG(ERROR) << "VideoSourceHandler::Close - Failed to find receiver that "
+               << "is associated with the given reader.";
+    return false;
+  }
   receiver->SetReader(NULL);
   source->RemoveSink(receiver);
   reader_to_receiver_.erase(reader);
   delete receiver;
   return true;
 }
 
 scoped_refptr<VideoSourceInterface> VideoSourceHandler::GetFirstVideoSource(
     const std::string& url) {
   scoped_refptr<webrtc::VideoSourceInterface> source;
@@ skipping 36 matching lines @@
   std::map<FrameReaderInterface*, VideoRenderer*>::iterator it;
   it = reader_to_receiver_.find(reader);
   if (it == reader_to_receiver_.end()) {
     return NULL;
   }
   return it->second;
 }
 
 }  // namespace content