Allow content embedders to create AudioManager.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 4398ba8aafd3b3cc0b934350421953ecf6cf3caa..879fe606a7c217bbcc47de6d5927b1f07ca3e2d8 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -55,6 +55,8 @@ class ImageSkia;
 }
 
 namespace media {
+class AudioLogFactory;
+class AudioManager;
 class CdmFactory;
 }
 
@@ -705,6 +707,11 @@ class CONTENT_EXPORT ContentBrowserClient {
   virtual ScopedVector<NavigationThrottle> CreateThrottlesForNavigation(
       NavigationHandle* navigation_handle);
 
+  // Allows the embedder to provide its own AudioManager implementation.
+  // If this function returns NULL, a default platform implementation will be

[jam, 2016/04/25 15:40:47]

nit: nullptr

[alokp, 2016/04/25 16:59:53]

Done.

+  // used. The caller owns the returned AudioManager instance.
+  virtual media::AudioManager* CreateAudioManager(

[DaleCurtis, 2016/04/22 23:45:06]

If caller owns, should return a scoped_ptr?

[alokp, 2016/04/22 23:54:21]

Since we are using ScopedAudioManagerPtr, it would require including
media/audio/audio_manager.h unnecessarily in content/public. This seems to be a
common pattern in this file to avoid including stuff.

[jam, 2016/04/25 15:40:47]

it's definitely fine to include headers from "lower-level" modules like
net/media/cc etc in content/public. So feel free to include that to make
ownership clearer.

[alokp, 2016/04/25 16:59:53]

DONE. I had to update DEPS - PTAL.

+      media::AudioLogFactory* audio_log_factory);
   // Creates and returns a factory used for creating CDM instances for playing
   // protected content.
   virtual std::unique_ptr<media::CdmFactory> CreateCdmFactory();