Intiialize AudioManager and related class lazily

content/browser/browser_main_loop.h

Index: content/browser/browser_main_loop.h
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index f970dc6aabbe40a4867c48fc6460dfd108b0a9f9..b8e871d46d02f9d8f12df712d4b8839109753a2d 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -122,6 +122,7 @@ class CONTENT_EXPORT BrowserMainLoop {
 
   int GetResultCode() const { return result_code_; }
 
+  void InitializeMediaComponentsIfNeeded();
   media::AudioManager* audio_manager() const { return audio_manager_.get(); }
   MediaStreamManager* media_stream_manager() const {
     return media_stream_manager_.get();
@@ -171,7 +172,6 @@ class CONTENT_EXPORT BrowserMainLoop {
   void InitStartupTracingForDuration(const base::CommandLine& command_line);
   void EndStartupTracing();
 
-  void CreateAudioManager();
   bool UsingInProcessGpu() const;
 
   // Quick reference for initialization order: