Reverted the code for the non-interactive audible tab notification

content/browser/media/audio_state_provider.h

-// Copyright 2015 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_MEDIA_AUDIO_STATE_PROVIDER_H_
-#define CONTENT_BROWSER_MEDIA_AUDIO_STATE_PROVIDER_H_
-
-#include "content/common/content_export.h"
-
-namespace content {
-class WebContents;
-class AudioStreamMonitor;
-
-// This class is associated with a WebContents, and maintains the audible
-// state regarding all the players in it.
-// The audible state is true if at least one player is playing a sound.
-// Whenever the audible state of the WebContents as a whole changes, this
-// class sends a notification to it.
-//
-// Each WebContentsImpl owns an AudioStateProvider
-class CONTENT_EXPORT AudioStateProvider {
- public:
-  explicit AudioStateProvider(WebContents* web_contents);
-  virtual ~AudioStateProvider() {}
-
-  // Indicates whether this service is available on the system.
-  virtual bool IsAudioStateAvailable() const = 0;
-
-  // If this provider uses monitoring (i.e. measure the signal),
-  // return its monitor.
-  virtual AudioStreamMonitor* audio_stream_monitor() = 0;
-
-  // Returns true if the WebContents is playing or has recently been
-  // playing the sound.
-  virtual bool WasRecentlyAudible() const;
-
-  void set_was_recently_audible_for_testing(bool value) {
-    was_recently_audible_ = value;
-  }
-
- protected:
-  // Notify WebContents that the audio state has changed.
-  void Notify(bool new_state);
-
-  // The WebContents instance instance to receive indicator toggle
-  // notifications.  This pointer should be valid for the lifetime of
-  // AudioStreamMonitor.
-  WebContents* const web_contents_;
-
-  // The audio state that is being maintained
-  bool  was_recently_audible_;
-
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_MEDIA_AUDIO_STATE_PROVIDER_H_