Fix a memory leak caused by AudioRenedererHost.

Fix a memory leak caused by AudioRenedererHost.

BUG=7608
AudioManager::CreateAudioManager() saves the instance in a static
variable and let it leak, so don't call it until there's a better
lifetime management of it.

[Erik does not do reviews, 2009-02-12 00:40:26]

http://codereview.chromium.org/21277/diff/4/1003
File chrome/browser/renderer_host/audio_renderer_host.cc (right):

http://codereview.chromium.org/21277/diff/4/1003#newcode196
Line 196: // AudioManager::GetAudioManager();
Why not change AudioManager to use base/Singleton?

http://codereview.chromium.org/21277/diff/4/1004
File chrome/browser/renderer_host/audio_renderer_host_unittest.cc (right):

http://codereview.chromium.org/21277/diff/4/1004#newcode16
Line 16: host_ = new AudioRendererHost(message_loop_.get());
I don't think this changes anything.  I think the issue here is that Destroy()
does a post task to do the deletion.  If the MessageLoop never runs again, then
it won't get destroyed.  In TearDown, you need to tell the message_loop_ to
RunAllPending().

[Alpha Left Google, 2009-02-12 01:16:00]

http://codereview.chromium.org/21277/diff/4/1003
File chrome/browser/renderer_host/audio_renderer_host.cc (right):

http://codereview.chromium.org/21277/diff/4/1003#newcode196
Line 196: // AudioManager::GetAudioManager();
On 2009/02/12 00:40:26, Erik Kay wrote:
> Why not change AudioManager to use base/Singleton?

~AudioManager() is private, I need to talk to cpu to see how to change that too.
So it's good for the moment, nothing is actually using AudioRendererHost.

[Erik does not do reviews, 2009-02-12 01:34:21]

LGTM

http://codereview.chromium.org/21277/diff/4/1003
File chrome/browser/renderer_host/audio_renderer_host.cc (right):

http://codereview.chromium.org/21277/diff/4/1003#newcode196
Line 196: // AudioManager::GetAudioManager();
On 2009/02/12 01:16:00, Alpha wrote:
> On 2009/02/12 00:40:26, Erik Kay wrote:
> > Why not change AudioManager to use base/Singleton?
> 
> ~AudioManager() is private, I need to talk to cpu to see how to change that
too.
> So it's good for the moment, nothing is actually using AudioRendererHost.

OK.  I think you should at least update the TODO to reflect the real problem
which is that you need to implement it as a proper Singleton.

FYI, it's common in Singleton use for the constructor to be private.  To work
around that, you need to add a friend declaration to your class, which would
also fix the private destructor problem (but perhaps not the underlying reason
that required the destructor to be private).

friend struct DefaultSingletonTraits<AudioManager>;