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

content/browser/renderer_host/clipboard_message_filter.cc

Index: content/browser/renderer_host/clipboard_message_filter.cc
===================================================================
--- content/browser/renderer_host/clipboard_message_filter.cc	(revision 271040)
+++ content/browser/renderer_host/clipboard_message_filter.cc	(working copy)
@@ -77,10 +77,9 @@
 #endif
 }
 
-bool ClipboardMessageFilter::OnMessageReceived(const IPC::Message& message,
-                                               bool* message_was_ok) {
+bool ClipboardMessageFilter::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP_EX(ClipboardMessageFilter, message, *message_was_ok)
+  IPC_BEGIN_MESSAGE_MAP(ClipboardMessageFilter, message)
     IPC_MESSAGE_HANDLER(ClipboardHostMsg_WriteObjectsAsync, OnWriteObjectsAsync)
     IPC_MESSAGE_HANDLER(ClipboardHostMsg_WriteObjectsSync, OnWriteObjectsSync)
     IPC_MESSAGE_HANDLER(ClipboardHostMsg_GetSequenceNumber, OnGetSequenceNumber)