Introduce the Background Fetch module.

third_party/WebKit/Source/modules/background_fetch/BackgroundFetchManager.h

+// 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 BackgroundFetchManager_h
+#define BackgroundFetchManager_h
+
+#include "bindings/core/v8/ScriptPromise.h"
+#include "bindings/core/v8/ScriptWrappable.h"
+#include "platform/heap/GarbageCollected.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class ScriptState;
+class ServiceWorkerRegistration;
+
+// Implementation of the BackgroundFetchManager JavaScript object, accessible
+// by developers through ServiceWorkerRegistration.backgroundFetch.
+class BackgroundFetchManager final
+    : public GarbageCollected<BackgroundFetchManager>,
+      public ScriptWrappable {
+  DEFINE_WRAPPERTYPEINFO();
+
+ public:
+  static BackgroundFetchManager* create(
+      ServiceWorkerRegistration* registration) {
+    return new BackgroundFetchManager(registration);
+  }
+
+  ScriptPromise getTags(ScriptState*);
+
+  DECLARE_TRACE();
+
+ private:
+  explicit BackgroundFetchManager(ServiceWorkerRegistration*);
+
+  Member<ServiceWorkerRegistration> m_registration;
+};
+
+}  // namespace blink
+
+#endif  // BackgroundFetchManager_h