Change WebMediaPlayer::GetAudioSourceProvider to return WebAudioSourceProviderImpl

... ref counted, instead of a raw WebAudioSourceProvider*.

This is now possible after webaudiosourceprovider_impl.cc|h was Onion
soup'ed [1].

[1] crrev.com/c/1629948

Reason: the original point of returning * so that no one would take refs.
But if someone is taking refs code should be changed to pass scoped_reptr.

BUG=787261
[email protected], [email protected]

Change-Id: I1545e1a846ccf258e833179ae971ae713c22406f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1637335
Commit-Queue: Antonio Gomes <[email protected]>
Reviewed-by: Dale Curtis <[email protected]>
Reviewed-by: Kentaro Hara <[email protected]>
Cr-Commit-Position: refs/heads/master@{#665036}
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 04e9c53..77f7ec4 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -2737,8 +2737,9 @@
   client_->ReadyStateChanged();
 }
 
-blink::WebAudioSourceProvider* WebMediaPlayerImpl::GetAudioSourceProvider() {
-  return audio_source_provider_.get();
+scoped_refptr<blink::WebAudioSourceProviderImpl>
+WebMediaPlayerImpl::GetAudioSourceProvider() {
+  return audio_source_provider_;
 }
 
 scoped_refptr<VideoFrame> WebMediaPlayerImpl::GetCurrentFrameFromCompositor()