Mojo cpp bindings: remove IsNonNullableValidationEnabled() check

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/public/cpp/bindings/lib/validation_errors.h"
 
 #include "mojo/public/cpp/environment/logging.h"
 
 namespace mojo {
 namespace internal {
@@ skipping 37 matching lines @@
   if (g_validation_error_observer)
     g_validation_error_observer->set_last_error(error);
   else
     MOJO_LOG(ERROR) << "Invalid message: " << ValidationErrorToString(error);
 }
 
 ValidationErrorObserverForTesting::ValidationErrorObserverForTesting()
     : last_error_(VALIDATION_ERROR_NONE) {
   MOJO_DCHECK(!g_validation_error_observer);
   g_validation_error_observer = this;
-  MOJO_LOG(WARNING) << "Non-nullable validation is turned on for testing but "
-                    << "not for production code yet!";
 }
 
 ValidationErrorObserverForTesting::~ValidationErrorObserverForTesting() {
   MOJO_DCHECK(g_validation_error_observer == this);
   g_validation_error_observer = NULL;
 }
 
 bool ReportSerializationWarning(ValidationError error) {
   if (g_serialization_warning_observer) {
     g_serialization_warning_observer->set_last_warning(error);
     return true;
   }
 
   return false;
 }
 
 SerializationWarningObserverForTesting::SerializationWarningObserverForTesting()
     : last_warning_(VALIDATION_ERROR_NONE) {
   MOJO_DCHECK(!g_serialization_warning_observer);
   g_serialization_warning_observer = this;
 }
 
 SerializationWarningObserverForTesting::
 ~SerializationWarningObserverForTesting() {
   MOJO_DCHECK(g_serialization_warning_observer == this);
   g_serialization_warning_observer = NULL;
 }
 
-bool IsNonNullableValidationEnabled() {
-  // TODO(yzshen): Remove this function and all call sites.
-  return true;
-}
-
 }  // namespace internal
 }  // namespace mojo