mojo::Serialize*_() calls now propogate/return validation errors.

mojo/public/cpp/bindings/lib/control_message_proxy.cc

Index: mojo/public/cpp/bindings/lib/control_message_proxy.cc
diff --git a/mojo/public/cpp/bindings/lib/control_message_proxy.cc b/mojo/public/cpp/bindings/lib/control_message_proxy.cc
index ee1e695bbd2d86bbf304f3d4a58dcda9d97fca7f..5b1491159ccfc32da5157273a6112bec54c754c7 100644
--- a/mojo/public/cpp/bindings/lib/control_message_proxy.cc
+++ b/mojo/public/cpp/bindings/lib/control_message_proxy.cc
@@ -52,7 +52,8 @@ void SendRunMessage(MessageReceiverWithResponder* receiver,
   RequestMessageBuilder builder(kRunMessageId, size);
 
   RunMessageParams_Data* params = nullptr;
-  Serialize_(params_ptr.get(), builder.buffer(), &params);
+  MOJO_DCHECK(Serialize_(params_ptr.get(), builder.buffer(), &params) ==
+              ValidationError::VALIDATION_ERROR_NONE);
   params->EncodePointersAndHandles(builder.message()->mutable_handles());
   MessageReceiver* responder = new RunResponseForwardToCallback(callback);
   if (!receiver->AcceptWithResponder(builder.message(), responder))
@@ -70,7 +71,8 @@ void SendRunOrClosePipeMessage(MessageReceiverWithResponder* receiver,
   MessageBuilder builder(kRunOrClosePipeMessageId, size);
 
   RunOrClosePipeMessageParams_Data* params = nullptr;
-  Serialize_(params_ptr.get(), builder.buffer(), &params);
+  MOJO_DCHECK(Serialize_(params_ptr.get(), builder.buffer(), &params) ==
+              ValidationError::VALIDATION_ERROR_NONE);
   params->EncodePointersAndHandles(builder.message()->mutable_handles());
   bool ok = receiver->Accept(builder.message());
   MOJO_ALLOW_UNUSED_LOCAL(ok);