Revert of Revert of Propagate audible state from player to the containing tab"

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 7d3766006456ddf20376ef8faee2abcfb4eae3a1..5d51ed15e1126ee4cc38385cde2171e82d2739d3 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -108,6 +108,7 @@
 #if defined(OS_ANDROID)
 #include "content/browser/android/content_video_view.h"
 #include "content/browser/android/date_time_chooser_android.h"
+#include "content/browser/android/media_players_observer.h"
 #include "content/browser/media/android/browser_media_player_manager.h"
 #include "content/browser/web_contents/web_contents_android.h"
 #endif
@@ -358,7 +359,6 @@ WebContentsImpl::WebContentsImpl(BrowserContext* browser_context,
       geolocation_service_context_(new GeolocationServiceContext()),
       accessibility_mode_(
           BrowserAccessibilityStateImpl::GetInstance()->accessibility_mode()),
-      audio_stream_monitor_(this),
       virtual_keyboard_requested_(false),
       loading_weak_factory_(this) {
   frame_tree_.SetFrameRemoveListener(
@@ -367,6 +367,12 @@ WebContentsImpl::WebContentsImpl(BrowserContext* browser_context,
 #if defined(ENABLE_BROWSER_CDMS)
   media_web_contents_observer_.reset(new MediaWebContentsObserver(this));
 #endif
+
+#if defined(OS_ANDROID)
+  audio_state_provider_.reset(new MediaPlayersObserver(this));
+#else
+  audio_state_provider_.reset(new AudioStreamMonitor(this));
+#endif
 }
 
 WebContentsImpl::~WebContentsImpl() {
@@ -1041,7 +1047,7 @@ void WebContentsImpl::NotifyNavigationStateChanged(
   // Create and release the audio power save blocker depending on whether the
   // tab is actively producing audio or not.
   if ((changed_flags & INVALIDATE_TYPE_TAB) &&
-      AudioStreamMonitor::monitoring_available()) {
+      audio_state_provider_->IsAudioStateAvailable()) {
     if (WasRecentlyAudible()) {
       if (!audio_power_save_blocker_)
         CreateAudioPowerSaveBlocker();
@@ -2523,7 +2529,7 @@ void WebContentsImpl::InsertCSS(const std::string& css) {
 }
 
 bool WebContentsImpl::WasRecentlyAudible() {
-  return audio_stream_monitor_.WasRecentlyAudible();
+  return audio_state_provider_->WasRecentlyAudible();
 }
 
 void WebContentsImpl::GetManifest(const GetManifestCallback& callback) {
@@ -3210,7 +3216,7 @@ void WebContentsImpl::MaybeReleasePowerSaveBlockers() {
   // monitoring, release the audio power save blocker here instead of during
   // NotifyNavigationStateChanged().
   if (active_audio_players_.empty() &&
-      !AudioStreamMonitor::monitoring_available()) {
+      !audio_state_provider_->IsAudioStateAvailable()) {
     audio_power_save_blocker_.reset();
   }
 
@@ -3233,7 +3239,7 @@ void WebContentsImpl::OnMediaPlayingNotification(int64 player_cookie,
     // If we don't have audio stream monitoring, allocate the audio power save
     // blocker here instead of during NotifyNavigationStateChanged().
     if (!audio_power_save_blocker_ &&
-        !AudioStreamMonitor::monitoring_available()) {
+        !audio_state_provider_->IsAudioStateAvailable()) {
       CreateAudioPowerSaveBlocker();
     }
   }