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

content/browser/media/session/media_session_impl_service_routing_unittest.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/media_session_impl.h"
 
 #include <map>
 #include <memory>
 
 #include "base/memory/ptr_util.h"
@@ skipping 384 matching lines @@
       .WillOnce(InvokeWithoutArgs(&run_loop, &base::RunLoop::Quit));
 
   services_[sub_frame_]->EnableAction(blink::mojom::MediaSessionAction::PAUSE);
 
   MediaSessionImpl::Get(contents())
       ->DidReceiveAction(blink::mojom::MediaSessionAction::PAUSE);
 
   run_loop.Run();
 }
 
+TEST_F(MediaSessionImplServiceRoutingTest,
+       TestReceivingPauseActionWhenNoServiceRouted) {
+  CreateServiceForFrame(main_frame_);
+  CreateServiceForFrame(sub_frame_);
+
+  EXPECT_EQ(nullptr, ComputeServiceForRouting());
+
+  // This should not crash.
+  MediaSessionImpl::Get(contents())
+      ->DidReceiveAction(blink::mojom::MediaSessionAction::PAUSE);
+}
+
 }  // namespace content