Fix a crash when receiving PAUSE action but no service is routed

content/browser/media/session/media_session_impl.cc

 // Copyright 2015 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/media_session_impl.h"
 
 #include <algorithm>
 #include "content/browser/media/session/audio_focus_delegate.h"
 #include "content/browser/media/session/media_session_controller.h"
 #include "content/browser/media/session/media_session_player_observer.h"
@@ skipping 628 matching lines @@
   // 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();
+        routed_service_ ? routed_service_->GetRenderFrameHost() : nullptr;
     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) {
         player.observer->OnSetVolumeMultiplier(player.player_id,
                                                kDuckingVolumeMultiplier);
       }
     }
@@ skipping 60 matching lines @@
     if (!IsServiceActiveForRenderFrameHost(frame))
       continue;
     best_frame = frame;
     min_depth = depth;
   }
 
   return best_frame ? services_[best_frame] : nullptr;
 }
 
 }  // namespace content