[WIP Prototype] ES6 https://html.spec.whatwg.org/#fetch-a-single-module-script implementation

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 71 matching lines @@
 #include "core/dom/ElementCreationOptions.h"
 #include "core/dom/ElementDataCache.h"
 #include "core/dom/ElementRegistrationOptions.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContextTask.h"
 #include "core/dom/FrameRequestCallback.h"
 #include "core/dom/IntersectionObserverController.h"
 #include "core/dom/LayoutTreeBuilderTraversal.h"
 #include "core/dom/LiveNodeList.h"
+#include "core/dom/ModuleMap.h"
 #include "core/dom/MutationObserver.h"
 #include "core/dom/NodeChildRemovalTracker.h"
 #include "core/dom/NodeComputedStyle.h"
 #include "core/dom/NodeFilter.h"
 #include "core/dom/NodeIterator.h"
 #include "core/dom/NodeRareData.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/dom/NodeWithIndex.h"
 #include "core/dom/NthIndexCache.h"
 #include "core/dom/ProcessingInstruction.h"
@@ skipping 6328 matching lines @@
   return LayoutViewItem(m_layoutView);
 }
 
 PropertyRegistry* Document::propertyRegistry() {
   // TODO(timloh): When the flag is removed, return a reference instead.
   if (!m_propertyRegistry && RuntimeEnabledFeatures::cssVariables2Enabled())
     m_propertyRegistry = PropertyRegistry::create();
   return m_propertyRegistry;
 }
 
+ModuleMap* Document::ensureModuleMap() {
+  if (!RuntimeEnabledFeatures::moduleScriptsEnabled())
+    return nullptr;
+
+  if (!m_moduleMap) {
+    m_moduleMap = ModuleMap::create(frame(), fetcher());

[dominicc (has gone to gerrit), 2016/12/13 07:45:29]

maybeCreate? DCHECK? What if you don't have a frame?

[kouhei (in TOK), 2016/12/15 04:56:26]

Done in PS5

+  }
+
+  return m_moduleMap;
+}
+
 void Document::incrementPasswordCount() {
   ++m_passwordCount;
   if (isSecureContext() || m_passwordCount != 1) {
     // The browser process only cares about passwords on pages where the
     // top-level URL is not secure. Secure contexts must have a top-level
     // URL that is secure, so there is no need to send notifications for
     // password fields in secure contexts.
     //
     // Also, only send a message on the first visible password field; the
     // browser process doesn't care about the presence of additional
@@ skipping 60 matching lines @@
   visitor->trace(m_svgExtensions);
   visitor->trace(m_timeline);
   visitor->trace(m_compositorPendingAnimations);
   visitor->trace(m_contextDocument);
   visitor->trace(m_canvasFontCache);
   visitor->trace(m_intersectionObserverController);
   visitor->trace(m_snapCoordinator);
   visitor->trace(m_resizeObserverController);
   visitor->trace(m_propertyRegistry);
   visitor->trace(m_styleReattachDataMap);
+  visitor->trace(m_moduleMap);
   Supplementable<Document>::trace(visitor);
   TreeScope::trace(visitor);
   ContainerNode::trace(visitor);
   ExecutionContext::trace(visitor);
   SecurityContext::trace(visitor);
   SynchronousMutationNotifier::trace(visitor);
 }
 
 void Document::maybeRecordLoadReason(WouldLoadReason reason) {
   DCHECK(m_wouldLoadReason == Created || reason != Created);
@@ skipping 42 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif