Make createElement tag name case handling consistent for custom elements

third_party/WebKit/Source/core/dom/custom/CustomElementTestHelpers.cpp

+// Copyright 2016 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 "core/dom/custom/CustomElementTestHelpers.h"
+
+namespace blink {
+
+CustomElementDefinition* TestCustomElementDefinitionBuilder::build(
+    const CustomElementDescriptor& descriptor) {
+  return new TestCustomElementDefinition(descriptor);
+}
+
+}  // namespace blink