Fix webrtcAudioPrivate API to handle requests from <webview>s.

content/public/browser/render_process_host.h

Index: content/public/browser/render_process_host.h
diff --git a/content/public/browser/render_process_host.h b/content/public/browser/render_process_host.h
index 6ee9f2bab7d4e02ba79c5b287495e5cbb949d8bc..b74e38f20592baff448d2e28209a38cd98abdb02 100644
--- a/content/public/browser/render_process_host.h
+++ b/content/public/browser/render_process_host.h
@@ -5,6 +5,8 @@
 #ifndef CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_PROCESS_HOST_H_
 
+#include <list>
+
 #include "base/basictypes.h"
 #include "base/id_map.h"
 #include "base/process/kill.h"
@@ -26,6 +28,10 @@ namespace gpu {
 union ValueState;
 }
 
+namespace media {
+class AudioOutputController;
+}
+
 namespace content {
 class BrowserContext;
 class BrowserMessageFilter;
@@ -255,6 +261,16 @@ class CONTENT_EXPORT RenderProcessHost : public IPC::Sender,
   virtual void SendUpdateValueState(
       unsigned int target, const gpu::ValueState& state) = 0;
 
+  // Retrieves the list of AudioOutputController objects associated
+  // with this object and passes it to the callback you specify, on
+  // the same thread on which you called the method.
+  typedef std::list<scoped_refptr<media::AudioOutputController>>
+      AudioOutputControllerList;
+  typedef base::Callback<void(const AudioOutputControllerList&)>
+      GetAudioOutputControllersCallback;
+  virtual void GetAudioOutputControllers(
+      const GetAudioOutputControllersCallback& callback) const = 0;
+
   // Static management functions -----------------------------------------------
 
   // Flag to run the renderer in process.  This is primarily