Add metrics regarding concurrent audible tabs in Chromium.

content/browser/media/media_web_contents_observer.cc

 // Copyright 2014 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.
 
 #include "content/browser/media/media_web_contents_observer.h"
 
+#include "base/lazy_instance.h"
 #include "base/memory/scoped_ptr.h"
 #include "build/build_config.h"
+#include "content/browser/media/audible_metrics.h"
+#include "content/browser/media/audio_stream_monitor.h"
 #include "content/browser/power_save_blocker_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/frame_messages.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "ipc/ipc_message_macros.h"
 
 namespace content {
 
+namespace {
+
+static base::LazyInstance<AudibleMetrics> g_audible_metrics =

[DaleCurtis, 2016/01/15 19:02:03]

::Leaky

[mlamouri (slow - plz ping), 2016/01/19 12:18:43]

Done.

+    LAZY_INSTANCE_INITIALIZER;
+
+}  // anonymous namespace
+
 MediaWebContentsObserver::MediaWebContentsObserver(WebContents* web_contents)
     : WebContentsObserver(web_contents) {}
 
 MediaWebContentsObserver::~MediaWebContentsObserver() {}
 
+void MediaWebContentsObserver::WebContentsDestroyed() {
+  g_audible_metrics.Get().UpdateAudibleWebContentsState(web_contents(), false);
+}
+
 void MediaWebContentsObserver::RenderFrameDeleted(
     RenderFrameHost* render_frame_host) {
   ClearPowerSaveBlockers(render_frame_host);
 }
 
-void MediaWebContentsObserver::MaybeUpdateAudibleState(bool recently_audible) {
-  if (recently_audible) {
+void MediaWebContentsObserver::MaybeUpdateAudibleState() {
+  if (!AudioStreamMonitor::monitoring_available())
+    return;
+
+  AudioStreamMonitor* audio_stream_monitor =
+      static_cast<WebContentsImpl*>(web_contents())->audio_stream_monitor();
+
+  if (audio_stream_monitor->WasRecentlyAudible()) {
     if (!audio_power_save_blocker_)
       CreateAudioPowerSaveBlocker();
   } else {
     audio_power_save_blocker_.reset();
   }
+
+  g_audible_metrics.Get().UpdateAudibleWebContentsState(
+      web_contents(), audio_stream_monitor->IsCurrentlyAudible());
 }
 
 bool MediaWebContentsObserver::OnMessageReceived(
     const IPC::Message& msg,
     RenderFrameHost* render_frame_host) {
   bool handled = true;
   // TODO(dalecurtis): These should no longer be FrameHostMsg.
   IPC_BEGIN_MESSAGE_MAP_WITH_PARAM(MediaWebContentsObserver, msg,
                                    render_frame_host)
     IPC_MESSAGE_HANDLER(FrameHostMsg_MediaPlayingNotification,
@@ skipping 158 matching lines @@
   if (it == player_map->end())
     return;
 
   for (int64_t player_cookie : it->second)
     removed_players->insert(MediaPlayerId(render_frame_host, player_cookie));
 
   player_map->erase(it);
 }
 
 }  // namespace content