Use AudioStreamMonitor to control power save blocking.

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 501ae9aa0f4ed99da6be0385031b7cc5c55f39de..5c98256548fcedd504bd0a5c58d7cbd1573243e4 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -111,6 +111,13 @@
 #include "base/mac/foundation_util.h"
 #endif
 
+// Only do audio stream monitoring for platforms that use it for the tab media
+// indicator UI or the OOM killer.
+#if !defined(OS_ANDROID) && !defined(OS_IOS)
+#define AUDIO_STREAM_MONITORING
+#include "content/browser/media/audio_stream_monitor.h"
+#endif
+
 // Cross-Site Navigations
 //
 // If a WebContentsImpl is told to navigate to a different web site (as
@@ -1042,6 +1049,10 @@ void WebContentsImpl::WasShown() {
     rvh->ResizeRectChanged(GetRootWindowResizerRect());
   }
 
+  // Restore power save blocker if there are active video players running.
+  if (!active_media_players_.empty())
+    CreatePowerSaveBlocker();
+
   FOR_EACH_OBSERVER(WebContentsObserver, observers_, WasShown());
 
   should_normally_be_visible_ = true;
@@ -1066,6 +1077,9 @@ void WebContentsImpl::WasHidden() {
     }
   }
 
+  // Release any video power save blockers held as video is not visible.
+  power_save_blocker_.reset();
+
   FOR_EACH_OBSERVER(WebContentsObserver, observers_, WasHidden());
 
   should_normally_be_visible_ = false;
@@ -2388,6 +2402,15 @@ void WebContentsImpl::InsertCSS(const std::string& css) {
       GetMainFrame()->GetRoutingID(), css));
 }
 
+bool WebContentsImpl::WasRecentlyAudible() {
+#if !defined(AUDIO_STREAM_MONITORING)
+  return false;
+#else
+  AudioStreamMonitor* const monitor = AudioStreamMonitor::FromWebContents(this);
+  return monitor ? monitor->WasRecentlyAudible() : false;
+#endif
+}
+
 bool WebContentsImpl::FocusLocationBarByDefault() {
   NavigationEntry* entry = controller_.GetVisibleEntry();
   if (entry && entry->GetURL() == GURL(url::kAboutBlankURL))
@@ -2999,42 +3022,61 @@ void WebContentsImpl::OnUpdateFaviconURL(
                     DidUpdateFaviconURL(candidates));
 }
 
+void WebContentsImpl::CreatePowerSaveBlocker() {
+  DCHECK(!power_save_blocker_);
+  DCHECK(!active_media_players_.empty());
+  power_save_blocker_ = PowerSaveBlocker::Create(
+      PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep, "Playing Video");
+#if defined(OS_ANDROID)
+  static_cast<PowerSaveBlockerImpl*>(power_save_blocker_.get())
+      ->InitDisplaySleepBlocker(GetView()->GetNativeView());
+#endif
+}
+
 void WebContentsImpl::OnMediaPlayingNotification(int64 player_cookie,
                                                  bool has_video,
                                                  bool has_audio) {
 #if !defined(OS_CHROMEOS)
-  scoped_ptr<PowerSaveBlocker> blocker;
-  if (has_video) {
-    blocker = PowerSaveBlocker::Create(
-        PowerSaveBlocker::kPowerSaveBlockPreventDisplaySleep, "Playing video");
-#if defined(OS_ANDROID)
-    static_cast<PowerSaveBlockerImpl*>(blocker.get())
-        ->InitDisplaySleepBlocker(GetView()->GetNativeView());
+#if defined(AUDIO_STREAM_MONITORING)
+  // Don't handle audio if audio level analysis is available.
+  if (!has_video)
+    return;
 #endif
-  } else if (has_audio) {
-    blocker = PowerSaveBlocker::Create(
-        PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension, "Playing audio");
-  }
 
-  if (blocker) {
-    uintptr_t key = reinterpret_cast<uintptr_t>(render_frame_message_source_);
-    if (!power_save_blockers_.contains(key)) {
-      power_save_blockers_.add(key,
-                               make_scoped_ptr(new PowerSaveBlockerMapEntry));
-    }
-    PowerSaveBlockerMapEntry* map_entry =
-        power_save_blockers_.get(key);
-    map_entry->set(player_cookie, blocker.Pass());
-  }
+  // Track current status to see if we need to create a new blocker.
+  const bool had_no_player = active_media_players_.empty();
+
+  // Store tracking entries based on the RenderFrameHost.
+  const uintptr_t key =
+      reinterpret_cast<uintptr_t>(render_frame_message_source_);
+
+  ActiveMediaPlayerMap::iterator it = active_media_players_.find(key);
+  if (it != active_media_players_.end())
+    it->second++;
+  else
+    active_media_players_[key] = 1;
+
+  // If we're not hidden and just created a new video player, create a blocker.
+  if (had_no_player && !active_media_players_.empty() && !IsHidden())
+    CreatePowerSaveBlocker();
 #endif  // !defined(OS_CHROMEOS)
 }
 
 void WebContentsImpl::OnMediaPausedNotification(int64 player_cookie) {
 #if !defined(OS_CHROMEOS)
-  uintptr_t key = reinterpret_cast<uintptr_t>(render_frame_message_source_);
-  PowerSaveBlockerMapEntry* map_entry = power_save_blockers_.get(key);
-  if (map_entry)
-    map_entry->erase(player_cookie);
+  ActiveMediaPlayerMap::iterator it = active_media_players_.find(
+      reinterpret_cast<uintptr_t>(render_frame_message_source_));
+  if (it == active_media_players_.end())
+    return;
+  it->second--;
+  DCHECK_GE(it->second, 0);
+  // If there are no more active players in this RenderFrameHost, remove entry.
+  if (!it->second)
+    active_media_players_.erase(it);
+  // If there are no more active players at all, clear the power blocker.
+  if (active_media_players_.empty()) {
+    power_save_blocker_.reset();
+  }
 #endif  // !defined(OS_CHROMEOS)
 }
 
@@ -4203,17 +4245,22 @@ BrowserPluginEmbedder* WebContentsImpl::GetBrowserPluginEmbedder() const {
 void WebContentsImpl::ClearPowerSaveBlockers(
     RenderFrameHost* render_frame_host) {
 #if !defined(OS_CHROMEOS)
-  uintptr_t key = reinterpret_cast<uintptr_t>(render_frame_host);
-  scoped_ptr<PowerSaveBlockerMapEntry> map_entry =
-      power_save_blockers_.take_and_erase(key);
-  if (map_entry)
-    map_entry->clear();
+  ActiveMediaPlayerMap::iterator it = active_media_players_.find(
+      reinterpret_cast<uintptr_t>(render_frame_message_source_));
+  if (it == active_media_players_.end())
+    return;
+  active_media_players_.erase(it);
+
+  // If there are no more active players at all, clear the power blocker.
+  if (active_media_players_.empty())
+    power_save_blocker_.reset();
 #endif
 }
 
 void WebContentsImpl::ClearAllPowerSaveBlockers() {
 #if !defined(OS_CHROMEOS)
-  power_save_blockers_.clear();
+  active_media_players_.clear();
+  power_save_blocker_.reset();
 #endif
 }