Fix a crash that EnsureMediaStreamClient() does not guarantee media_stream_client_ get created

content/renderer/render_view_impl.cc

 // Copyright (c) 2012 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/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/auto_reset.h"
@@ skipping 2982 matching lines @@
   return NULL;
 }
 
 WebMediaPlayer* RenderViewImpl::createMediaPlayer(
     WebFrame* frame, const WebKit::WebURL& url, WebMediaPlayerClient* client) {
   FOR_EACH_OBSERVER(
       RenderViewObserver, observers_, WillCreateMediaPlayer(frame, client));
 
   const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
 #if defined(ENABLE_WEBRTC)
   EnsureMediaStreamClient();

[scherkus (not reviewing), 2013/08/23 22:21:40]

I know you want to merge this so we should keep it simple... but the code now
looks a bit silly (and I know I'm to blame here) because we have a function
called EnsureMSC() yet we're still required to check the result :)

can you add a TODO to EMSC() to rename it because it in fact doesn't ensure MSC
is created? (bet yet, feel free to fix it in a follow up CL)

 #if !defined(GOOGLE_TV)
-  if (media_stream_client_->IsMediaStream(url)) {
+  if (media_stream_client_ && media_stream_client_->IsMediaStream(url)) {
 #if defined(OS_ANDROID) && defined(ARCH_CPU_ARMEL)
     bool found_neon =
         (android_getCpuFeatures() & ANDROID_CPU_ARM_FEATURE_NEON) != 0;
     UMA_HISTOGRAM_BOOLEAN("Platform.WebRtcNEONFound", found_neon);
 #endif  // defined(OS_ANDROID) && defined(ARCH_CPU_ARMEL)
     return new WebMediaPlayerMS(
         frame, client, AsWeakPtr(), media_stream_client_, new RenderMediaLog());
   }
 #endif  // !defined(GOOGLE_TV)
 #endif  // defined(ENABLE_WEBRTC)
@@ skipping 3520 matching lines @@
     WebURL url = icon_urls[i].iconURL();
     if (!url.isEmpty())
       urls.push_back(FaviconURL(url,
                                 ToFaviconType(icon_urls[i].iconType())));
   }
   SendUpdateFaviconURL(urls);
 }
 
 
 }  // namespace content