Delete MediaStreamManager in the same way as AudioManager

content/browser/renderer_host/media/media_stream_device_settings.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/browser/renderer_host/media/media_stream_device_settings.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 25 matching lines @@
 class ResponseCallbackHelper
     : public base::RefCountedThreadSafe<ResponseCallbackHelper> {
  public:
   explicit ResponseCallbackHelper(
       base::WeakPtr<media_stream::MediaStreamDeviceSettings> settings)
       : settings_(settings) {
   }
 
   void PostResponse(const std::string& label,
                     const content::MediaStreamDevices& devices) {
+    if (!settings_)

[tommi (sloooow) - chröme, 2012/07/18 08:15:23]

it's better to do this check only on the IO thread as it was before.  This
change makes it so that we're checking the variable on more than one thread.

[no longer working on chromium, 2012/07/18 09:39:28]

But can BrowserThread::PostTask(BrowserThread::IO, .. crash when the IO thread
has gone away?

+      return;
+
     if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
       BrowserThread::PostTask(
           BrowserThread::IO, FROM_HERE,
           base::Bind(&media_stream::MediaStreamDeviceSettings::PostResponse,
                      settings_, label, devices));
       return;
-    } else if (settings_) {
-      settings_->PostResponse(label, devices);
     }
+
+    settings_->PostResponse(label, devices);
   }
 
  private:
   friend class base::RefCountedThreadSafe<ResponseCallbackHelper>;
   ~ResponseCallbackHelper() {}
 
   base::WeakPtr<media_stream::MediaStreamDeviceSettings> settings_;
 
   DISALLOW_COPY_AND_ASSIGN(ResponseCallbackHelper);
 };
@@ skipping 300 matching lines @@
   content::MediaResponseCallback callback =
       base::Bind(&ResponseCallbackHelper::PostResponse,
                  helper.get(), label);
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&DoDeviceRequest, *request, callback));
 }
 
 }  // namespace media_stream