Defer media playback in background tabs.

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index 05e6ad6f8c49c076f229b9ebe655ec73dbc4ad97..5b7b7187210ba3ec1b7451dc702b85f6b024ef83 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -684,6 +684,7 @@ RenderFrameImpl::RenderFrameImpl(const CreateParams& params)
       manifest_manager_(NULL),
       accessibility_mode_(AccessibilityModeOff),
       renderer_accessibility_(NULL),
+      has_played_media_(false),
       weak_factory_(this) {
   std::pair<RoutingIDFrameMap::iterator, bool> result =
       g_routing_id_frame_map.Get().insert(std::make_pair(routing_id_, this));
@@ -2041,7 +2042,7 @@ blink::WebMediaPlayer* RenderFrameImpl::createMediaPlayer(
   media::WebMediaPlayerParams params(
       base::Bind(&ContentRendererClient::DeferMediaLoad,
                  base::Unretained(GetContentClient()->renderer()),
-                 static_cast<RenderFrame*>(this)),
+                 static_cast<RenderFrame*>(this), has_played_media_),
       render_thread->GetAudioRendererMixerManager()->CreateInput(routing_id_),
       media_log, render_thread->GetMediaThreadTaskRunner(),
       render_thread->compositor_task_runner(),
@@ -3827,6 +3828,7 @@ blink::WebVRClient* RenderFrameImpl::webVRClient() {
 #endif
 
 void RenderFrameImpl::DidPlay(WebMediaPlayer* player) {
+  has_played_media_ = true;
   Send(new FrameHostMsg_MediaPlayingNotification(
       routing_id_, reinterpret_cast<int64>(player), player->hasVideo(),
       player->hasAudio(), player->isRemote()));