Remove the AudioManager singleton.

chrome/browser/profiles/profile_io_data.cc

Index: chrome/browser/profiles/profile_io_data.cc
===================================================================
--- chrome/browser/profiles/profile_io_data.cc	(revision 113173)
+++ chrome/browser/profiles/profile_io_data.cc	(working copy)
@@ -496,7 +496,8 @@
     job_factory_->AddInterceptor(new chromeos::GViewRequestInterceptor);
 #endif  // defined(OS_CHROMEOS) && !defined(GOOGLE_CHROME_BUILD)
 
-  media_stream_manager_.reset(new media_stream::MediaStreamManager);
+  media_stream_manager_.reset(
+      new media_stream::MediaStreamManager(g_browser_process->audio_manager()));

[willchan no longer on Chromium, 2011/12/10 00:27:33]

Can you make audio_manager get passed in on the UI thread? There's actually a
small race since g_browser_process is a UI thread object and we're accessing it
on the IO thread. If the process shutdown immediately, it's actually
theoretically possible for this to be a use after free.

Also, I like to push use of globals as close to main() as possible, and pass
them into code.

[tommi (sloooow) - chröme, 2011/12/10 09:59:57]

Just so that I understand - do you mean that g_browser_process might possibly be
invalid or that the audio manager might be used after BrowserProcessImpl
releases its reference?

What I'll do then is to fetch the audio_manager inside InitializeOnUIThread and
pass it to here via profile_params_.  Sounds reasonable?
Is there perhaps a better way to share an object across more than one
ResourceContext instances than to keep it with BrowserProcessImpl?  If there is,
I can move the audio manager's home when I make the change to not have the audio
manager ref counted.

[willchan no longer on Chromium, 2011/12/12 16:44:05]

Sounds great and your change looks great to me.

 
   // Take ownership over these parameters.
   database_tracker_ = profile_params_->database_tracker;
@@ -523,6 +524,7 @@
       io_thread_globals->media.media_internals.get());
   resource_context_.set_download_id_factory(download_id_factory_);
   resource_context_.set_media_stream_manager(media_stream_manager_.get());
+  resource_context_.set_audio_manager(g_browser_process->audio_manager());
 
   LazyInitializeInternal(profile_params_.get());