Add compile time checks against longs being used in IPC structs on 32 bit Android.

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 69ea7cb6d8a08e68815c393fa099d60ce0e3bc62..7f0036876c96e98ba475baa684b2feda8922b20f 100644
--- a/ipc/ipc_message_utils.h
+++ b/ipc/ipc_message_utils.h
@@ -192,7 +192,12 @@ template <>
 struct ParamTraits<long> {
   typedef long param_type;
   static void Write(Message* m, const param_type& p) {
-    m->WriteLongUsingDangerousNonPortableLessPersistableForm(p);
+    // To ensure compatibility between 32-bit and 64-bit processes, send as
+    // 64 bit size. We can't check on the writing side if reading may overflow
+    // if sending from 64-bit process and reading from 32-bit process, since we
+    // don't know if this IPC parameter is 64 bit always (i.e. from an int64_t
+    // typedef) or if it's from a size_t.
+    m->WriteLong(p);
   }
   static bool Read(const Message* m,
                    base::PickleIterator* iter,
@@ -206,7 +211,8 @@ template <>
 struct ParamTraits<unsigned long> {
   typedef unsigned long param_type;
   static void Write(Message* m, const param_type& p) {
-    m->WriteLongUsingDangerousNonPortableLessPersistableForm(p);
+    // See comment in ParamTraits<long>::Write.
+    m->WriteLong(p);
   }
   static bool Read(const Message* m,
                    base::PickleIterator* iter,