Remove irrelevant DCHECK that could hit (and it's ok)

content/renderer/service_worker/embedded_worker_context_client.cc

 // Copyright 2013 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_context_client.h"
 
 #include "base/lazy_instance.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/pickle.h"
 #include "base/threading/thread_local.h"
@@ skipping 74 matching lines @@
     const GURL& script_url)
     : embedded_worker_id_(embedded_worker_id),
       service_worker_version_id_(service_worker_version_id),
       script_url_(script_url),
       sender_(ChildThread::current()->thread_safe_sender()),
       main_thread_proxy_(base::MessageLoopProxy::current()),
       weak_factory_(this) {
 }
 
 EmbeddedWorkerContextClient::~EmbeddedWorkerContextClient() {
-  DCHECK(g_worker_client_tls.Pointer()->Get() != NULL);
+  // g_worker_client_tls.Pointer()->Get() could be NULL if this gets
+  // deleted before workerContextStarted() is called.
   g_worker_client_tls.Pointer()->Set(NULL);
 }
 
 bool EmbeddedWorkerContextClient::OnMessageReceived(
     const IPC::Message& msg) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(EmbeddedWorkerContextClient, msg)
     IPC_MESSAGE_HANDLER(EmbeddedWorkerContextMsg_SendMessageToWorker,
                         OnSendMessageToWorker)
     IPC_MESSAGE_UNHANDLED(handled = false)
@@ skipping 120 matching lines @@
 }
 
 void EmbeddedWorkerContextClient::SendWorkerStarted() {
   DCHECK(worker_task_runner_->RunsTasksOnCurrentThread());
   sender_->Send(new EmbeddedWorkerHostMsg_WorkerStarted(
       WorkerTaskRunner::Instance()->CurrentWorkerId(),
       embedded_worker_id_));
 }
 
 }  // namespace content