Implement off-the-wire validation scheme for enum types.

ipc/param_traits_read_macros.h

Index: ipc/param_traits_read_macros.h
diff --git a/ipc/param_traits_read_macros.h b/ipc/param_traits_read_macros.h
index 3fc0ad1f0f05ff4151ff2bcc6ab5dcdcb7cdcfb9..296a84d334e59b3588e7feed5bdd14176b8ddf24 100644
--- a/ipc/param_traits_read_macros.h
+++ b/ipc/param_traits_read_macros.h
@@ -6,6 +6,7 @@
 #define IPC_PARAM_TRAITS_READ_MACROS_H_
 
 // Null out all the macros that need nulling.
+#include "base/enum_validation.h"
 #include "ipc/ipc_message_null_macros.h"
 
 // STRUCT declarations cause corresponding STRUCT_TRAITS declarations to occur.
@@ -39,6 +40,8 @@
     int type; \
     if (!m->ReadInt(iter, &type)) \
       return false; \
+    if (!IsIntValidForEnum<param_type>(type)) \
+      return false; \
     *p = static_cast<param_type>(type); \
     return true; \
   }