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

third_party/WebKit/Source/core/loader/modulescript/ModuleTreeLinkerRegistry.h

Index: third_party/WebKit/Source/core/loader/modulescript/ModuleTreeLinkerRegistry.h
diff --git a/third_party/WebKit/Source/core/loader/modulescript/ModuleTreeLinkerRegistry.h b/third_party/WebKit/Source/core/loader/modulescript/ModuleTreeLinkerRegistry.h
new file mode 100644
index 0000000000000000000000000000000000000000..509b7e6d4742d4b47ad6054a4fe66cce61a9136e
--- /dev/null
+++ b/third_party/WebKit/Source/core/loader/modulescript/ModuleTreeLinkerRegistry.h
@@ -0,0 +1,45 @@
+// Copyright 2017 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.
+
+#ifndef ModuleTreeLinkerRegistry_h
+#define ModuleTreeLinkerRegistry_h
+
+#include "core/dom/AncestorList.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class Modulator;
+class ModuleScriptFetchRequest;
+class ModuleTreeClient;
+class ModuleTreeLinker;
+enum class ModuleGraphLevel;
+
+// ModuleTreeLinkerRegistry keeps active ModuleTreeLinkers alive.
+class ModuleTreeLinkerRegistry
+    : public GarbageCollected<ModuleTreeLinkerRegistry> {
+ public:
+  static ModuleTreeLinkerRegistry* create() {
+    return new ModuleTreeLinkerRegistry;
+  }
+  DECLARE_TRACE();
+
+  ModuleTreeLinker* fetch(const ModuleScriptFetchRequest&,
+                          const AncestorList&,
+                          ModuleGraphLevel,
+                          Modulator*,
+                          ModuleTreeClient*);
+
+ private:
+  ModuleTreeLinkerRegistry() = default;
+
+  friend class ModuleTreeLinker;
+  void releaseFinishedFetcher(ModuleTreeLinker*);
+
+  HeapHashSet<Member<ModuleTreeLinker>> m_activeTreeLinkers;
+};
+
+}  // namespace blink
+
+#endif