Adding UMA to record whether Pepper players have ever played sound

content/browser/media/session/pepper_playback_observer.cc

 // Copyright 2016 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/session/pepper_playback_observer.h"
 
 #include "base/feature_list.h"
+#include "base/metrics/histogram_macros.h"
 #include "content/browser/media/session/media_session.h"
 #include "content/browser/media/session/pepper_player_delegate.h"
 #include "content/common/frame_messages.h"
 #include "ipc/ipc_message_macros.h"
 #include "media/base/media_switches.h"
 
 namespace content {
 
 PepperPlaybackObserver::PepperPlaybackObserver(WebContentsImpl *contents)
     : contents_(contents) {}
 
 PepperPlaybackObserver::~PepperPlaybackObserver() {
   // At this point WebContents is being destructed, so it's safe to
   // call this. MediaSession may decide to send further IPC messages
   // through PepperPlayerDelegates, which might be declined if the
   // RenderViewHost has been destroyed.
   for (PlayersMap::iterator iter = players_map_.begin();
        iter != players_map_.end();) {
     MediaSession::Get(contents_)->RemovePlayer(
         iter->second.get(), PepperPlayerDelegate::kPlayerId);
     iter = players_map_.erase(iter);
   }
 }
 
 void PepperPlaybackObserver::PepperInstanceCreated(int32_t pp_instance) {
+  players_played_sound_map_[pp_instance] = false;
 }
 
 void PepperPlaybackObserver::PepperInstanceDeleted(int32_t pp_instance) {
+

[mlamouri (slow - plz ping), 2016/07/06 14:17:05]

style: remove empty line.

+  UMA_HISTOGRAM_BOOLEAN("Media.Pepper.PlayedSound",
+                        players_played_sound_map_[pp_instance]);
+  players_played_sound_map_.erase(pp_instance);
+
   PepperStopsPlayback(pp_instance);
 }
 
 void PepperPlaybackObserver::PepperStartsPlayback(int32_t pp_instance) {
+  players_played_sound_map_[pp_instance] = true;
+
   if (!base::FeatureList::IsEnabled(media::kFlashJoinsMediaSession))
     return;
 
   if (players_map_.count(pp_instance))
     return;
 
   players_map_[pp_instance].reset(new PepperPlayerDelegate(
       contents_, pp_instance));
   MediaSession::Get(contents_)->AddPlayer(
       players_map_[pp_instance].get(),
       PepperPlayerDelegate::kPlayerId,
       MediaSession::Type::Content);
 }
 
 void PepperPlaybackObserver::PepperStopsPlayback(int32_t pp_instance) {
   if (!players_map_.count(pp_instance))
     return;
 
   MediaSession::Get(contents_)->RemovePlayer(
       players_map_[pp_instance].get(), PepperPlayerDelegate::kPlayerId);
 
   players_map_.erase(pp_instance);
 }
 
 }  // namespace content