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

content/renderer/service_worker/embedded_worker_context_client.cc

Index: content/renderer/service_worker/embedded_worker_context_client.cc
diff --git a/content/renderer/service_worker/embedded_worker_context_client.cc b/content/renderer/service_worker/embedded_worker_context_client.cc
index 337cfaa7d085e55252e6b9d7c93dca6d37340324..35929006d43749e21b17c4303dcf93157a531014 100644
--- a/content/renderer/service_worker/embedded_worker_context_client.cc
+++ b/content/renderer/service_worker/embedded_worker_context_client.cc
@@ -92,7 +92,8 @@ EmbeddedWorkerContextClient::EmbeddedWorkerContextClient(
 }
 
 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);
 }