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

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

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index b40ae4ad1496b3bb428b657b41cc41debda2c5c1..a64067574b01d56eafeeac40af646a438dc87708 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -89,6 +89,7 @@
 #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"
@@ -6453,6 +6454,17 @@ PropertyRegistry* Document::propertyRegistry() {
   return m_propertyRegistry;
 }
 
+ModuleMap* Document::ensureModuleMap() {
+  if (!RuntimeEnabledFeatures::moduleScriptsEnabled())
+    return nullptr;
+
+  if (!m_moduleMap) {
+    m_moduleMap = ModuleMap::create(frame(), fetcher());
+  }
+
+  return m_moduleMap;
+}
+
 void Document::incrementPasswordCount() {
   ++m_passwordCount;
   if (isSecureContext() || m_passwordCount != 1) {
@@ -6534,6 +6546,7 @@ DEFINE_TRACE(Document) {
   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);