Intiialize AudioManager and related class lazily

content/browser/browser_main_loop.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 #define CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 
 #include <memory>
 
 #include "base/files/file_path.h"
@@ skipping 104 matching lines @@
 
   // Perform the default message loop run logic.
   void RunMainMessageLoopParts();
 
   // Performs the shutdown sequence, starting with PostMainMessageLoopRun
   // through stopping threads to PostDestroyThreads.
   void ShutdownThreadsAndCleanUp();
 
   int GetResultCode() const { return result_code_; }
 
-  media::AudioManager* audio_manager() const { return audio_manager_.get(); }
-  MediaStreamManager* media_stream_manager() const {
-    return media_stream_manager_.get();
-  }
+  media::AudioManager* GetAudioManager();
+  MediaStreamManager* GetMediaStreamManager();
+  void InitializeSpeechRecognitionManager();
+
   media::UserInputMonitor* user_input_monitor() const {
     return user_input_monitor_.get();
   }
   media::midi::MidiManager* midi_manager() const { return midi_manager_.get(); }
   base::Thread* indexed_db_thread() const { return indexed_db_thread_.get(); }
 
   bool is_tracing_startup_for_duration() const {
     return is_tracing_startup_for_duration_;
   }
 
@@ skipping 25 matching lines @@
 
   int PreMainMessageLoopRun();
 
   void MainMessageLoopRun();
 
   base::FilePath GetStartupTraceFileName(
       const base::CommandLine& command_line) const;
   void InitStartupTracingForDuration(const base::CommandLine& command_line);
   void EndStartupTracing();
 
-  void CreateAudioManager();
   bool UsingInProcessGpu() const;
 
   // Quick reference for initialization order:
   // Constructor
   // Init()
   // EarlyInitialization()
   // InitializeToolkit()
   // PreMainMessageLoopStart()
   // MainMessageLoopStart()
   //   InitializeMainThread()
@@ skipping 102 matching lines @@
   std::unique_ptr<TimeZoneMonitor> time_zone_monitor_;
 
   // DO NOT add members here. Add them to the right categories above.
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_