[Media>Session] Pause all players for non-routed frames when receiving PAUSE action

content/browser/media/session/media_session_impl.cc

Index: content/browser/media/session/media_session_impl.cc
diff --git a/content/browser/media/session/media_session_impl.cc b/content/browser/media/session/media_session_impl.cc
index bedae34f22e869fb82ab0414fc1935706116fd5b..26448557519ca0ef5d1275658e14c68a0e830f84 100644
--- a/content/browser/media/session/media_session_impl.cc
+++ b/content/browser/media/session/media_session_impl.cc
@@ -611,6 +611,37 @@ void MediaSessionImpl::OnMediaSessionActionsChanged(
 
 void MediaSessionImpl::DidReceiveAction(
     blink::mojom::MediaSessionAction action) {
+  // Pause all players in non-routed frames if the action is PAUSE.
+  //
+  // This is the default PAUSE action handler as mentioned in the Media Session
+  // API spec. The reason for pausing all players in all other sessions is to
+  // avoid the players in other frames keep the session active so that the UI
+  // will always show the pause button but it does not pause anything (as the
+  // routed frame already pauses when responding to the PAUSE action while other
+  // frames does not).
+  //
+  // TODO(zqzhang): Currently, this might not work well on desktop as Pepper and
+  // OneShot players are not really suspended, so that the session is still
+  // active after this. See https://crbug.com/619084 and
+  // https://crbug.com/596516.
+  if (blink::mojom::MediaSessionAction::PAUSE == action) {
+    RenderFrameHost* rfh_of_routed_service =
+        routed_service_->GetRenderFrameHost();
+    for (const auto& player : normal_players_) {
+      if (player.observer->GetRenderFrameHost() != rfh_of_routed_service)
+        player.observer->OnSuspend(player.player_id);
+    }
+    for (const auto& player : pepper_players_) {
+      if (player.observer->GetRenderFrameHost() != rfh_of_routed_service)

[mlamouri (slow - plz ping), 2017/02/10 14:17:43]

styte: you need { } because the statement is in two lines (wrapping)

[Zhiqiang Zhang (Slow), 2017/02/10 14:25:58]

Done.

+        player.observer->OnSetVolumeMultiplier(
+            player.player_id, kDuckingVolumeMultiplier);
+    }
+    for (const auto& player : one_shot_players_) {
+      if (player.observer->GetRenderFrameHost() != rfh_of_routed_service)
+        player.observer->OnSuspend(player.player_id);
+    }
+  }
+
   if (!routed_service_)
     return;