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

content/browser/renderer_host/render_view_host_impl.h

Index: content/browser/renderer_host/render_view_host_impl.h
diff --git a/content/browser/renderer_host/render_view_host_impl.h b/content/browser/renderer_host/render_view_host_impl.h
index fee923503a27f0498d628f929d872c9871610e09..cc071844bd28dc51f06c5ae3597bba28847975a5 100644
--- a/content/browser/renderer_host/render_view_host_impl.h
+++ b/content/browser/renderer_host/render_view_host_impl.h
@@ -168,8 +168,6 @@ class CONTENT_EXPORT RenderViewHostImpl
   WebPreferences GetWebkitPreferences() override;
   void UpdateWebkitPreferences(const WebPreferences& prefs) override;
   void OnWebkitPreferencesChanged() override;
-  void GetAudioOutputControllers(
-      const GetAudioOutputControllersCallback& callback) const override;
   void SelectWordAroundCaret() override;
 
 #if defined(OS_ANDROID)