Generate param traits size methods for IPC files in content/ (and traits it depends on).

ipc/ipc_message_utils.h

Index: ipc/ipc_message_utils.h
diff --git a/ipc/ipc_message_utils.h b/ipc/ipc_message_utils.h
index 2c4570311ef79749d93cffe454fc66def6c0926c..0de489bfb38c8bd982a0639f5b25855d35a90751 100644
--- a/ipc/ipc_message_utils.h
+++ b/ipc/ipc_message_utils.h
@@ -554,6 +554,7 @@ struct IPC_EXPORT ParamTraits<base::DictionaryValue> {
 template<>
 struct IPC_EXPORT ParamTraits<base::FileDescriptor> {
   typedef base::FileDescriptor param_type;
+  static void GetSize(base::PickleSizer* sizer, const param_type& p);
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,
@@ -566,6 +567,7 @@ struct IPC_EXPORT ParamTraits<base::FileDescriptor> {
 template <>
 struct IPC_EXPORT ParamTraits<base::SharedMemoryHandle> {
   typedef base::SharedMemoryHandle param_type;
+  static void GetSize(base::PickleSizer* sizer, const param_type& p);
   static void Write(base::Pickle* m, const param_type& p);
   static bool Read(const base::Pickle* m,
                    base::PickleIterator* iter,