Add runtime flag for <script type="module">

third_party/WebKit/Source/core/dom/ScriptLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 157 matching lines @@
     // - Allowing a different set of languages for language= and type=. language= supports Javascript 1.1 and 1.4-1.6, but type= does not.
 
     String type = client()->typeAttributeValue();
     String language = client()->languageAttributeValue();
     if (type.isEmpty() && language.isEmpty())
         return true; // Assume text/javascript.
     if (type.isEmpty()) {
         type = "text/" + language.lower();
         if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type) || isLegacySupportedJavaScriptLanguage(language))
             return true;
+    } else if (RuntimeEnabledFeatures::moduleScriptsEnabled() && type == "module") {
+        return true;
     } else if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(type.stripWhiteSpace()) || (supportLegacyTypes == AllowLegacyTypeInTypeAttribute && isLegacySupportedJavaScriptLanguage(type))) {
         return true;
     }
 
     return false;
 }
 
 // http://dev.w3.org/html5/spec/Overview.html#prepare-a-script
 bool ScriptLoader::prepareScript(const TextPosition& scriptStartPosition, LegacyTypeSupport supportLegacyTypes)
 {
@@ skipping 325 matching lines @@
     if (isHTMLScriptLoader(element))
         return toHTMLScriptElement(element)->loader();
 
     if (isSVGScriptLoader(element))
         return toSVGScriptElement(element)->loader();
 
     return 0;
 }
 
 } // namespace blink