Remove IPC_BEGIN_MESSAGE_MAP_EX macro since r270839 made all bad IPCs kill their child processes.

content/browser/service_worker/service_worker_dispatcher_host.cc

Index: content/browser/service_worker/service_worker_dispatcher_host.cc
===================================================================
--- content/browser/service_worker/service_worker_dispatcher_host.cc	(revision 271040)
+++ content/browser/service_worker/service_worker_dispatcher_host.cc	(working copy)
@@ -85,11 +85,9 @@
 }
 
 bool ServiceWorkerDispatcherHost::OnMessageReceived(
-    const IPC::Message& message,
-    bool* message_was_ok) {
+    const IPC::Message& message) {
   bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP_EX(
-    ServiceWorkerDispatcherHost, message, *message_was_ok)
+  IPC_BEGIN_MESSAGE_MAP(ServiceWorkerDispatcherHost, message)
     IPC_MESSAGE_HANDLER(ServiceWorkerHostMsg_RegisterServiceWorker,
                         OnRegisterServiceWorker)
     IPC_MESSAGE_HANDLER(ServiceWorkerHostMsg_UnregisterServiceWorker,