Move resource related IPCs to their own file in content.  I added a IPC_STRUCT_TRAITS_PARENT macro to allow the automatic serializing macros to add a parent struct.

TBR=tsepez
Review URL: http://codereview.chromium.org/6628035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@77048 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ipc/ipc_message_utils.h b/ipc/ipc_message_utils.h
index f7bf49a0..800daaf 100644
--- a/ipc/ipc_message_utils.h
+++ b/ipc/ipc_message_utils.h
@@ -71,6 +71,7 @@
   SafeBrowsingMsgStart,
   P2PMsgStart,
   SocketStreamMsgStart,
+  ResourceMsgStart,
 };
 
 class DictionaryValue;