ServiceWorker: check if StopWorker is called twice

content/renderer/service_worker/embedded_worker_instance_client_impl.cc

 // Copyright (c) 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/renderer/service_worker/embedded_worker_instance_client_impl.h"
 
 #include <memory>
 
 #include "base/strings/utf_string_conversions.h"
 #include "content/child/scoped_child_process_reference.h"
@@ skipping 51 matching lines @@
                       params.script_url, params.worker_devtools_agent_route_id,
                       std::move(temporal_self_)));
   wrapper_ = wrapper.get();
   dispatcher_->RegisterWorker(params.embedded_worker_id, std::move(wrapper));
 }
 
 void EmbeddedWorkerInstanceClientImpl::StopWorker(
     const StopWorkerCallback& callback) {
   DCHECK(ChildThreadImpl::current());
   DCHECK(embedded_worker_id_);
-  DCHECK(!stop_callback_);
+  // StopWorker is possible to be called twice.
+  if (stop_callback_) {
+    LOG(WARNING) << "Got StopWorker for stopping worker";
+    return;
+  }
   TRACE_EVENT0("ServiceWorker", "EmbeddedWorkerInstanceClientImpl::StopWorker");
   stop_callback_ = std::move(callback);
   dispatcher_->RecordStopWorkerTimer(embedded_worker_id_.value());
   wrapper_->worker()->terminateWorkerContext();
 }
 
 EmbeddedWorkerInstanceClientImpl::EmbeddedWorkerInstanceClientImpl(
     EmbeddedWorkerDispatcher* dispatcher,
     mojo::InterfaceRequest<mojom::EmbeddedWorkerInstanceClient> request)
     : dispatcher_(dispatcher),
       binding_(this, std::move(request)),
       temporal_self_(std::unique_ptr<EmbeddedWorkerInstanceClientImpl>(this)) {
   binding_.set_connection_error_handler(base::Bind(
       &EmbeddedWorkerInstanceClientImpl::OnError, base::Unretained(this)));
 }
 
 EmbeddedWorkerInstanceClientImpl::~EmbeddedWorkerInstanceClientImpl() {}
 
 void EmbeddedWorkerInstanceClientImpl::OnError() {
   // Removes myself if it's owned by myself.
   temporal_self_.reset();
 }
 
 }  // namespace content