Define push_messaging module with PushManager skeleton.

Source/modules/push_messaging/PushManager.h

+// Copyright 2014 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 PushManager_h
+#define PushManager_h
+
+#include "bindings/v8/ScriptWrappable.h"
+#include "wtf/text/WTFString.h"
+

[Peter Beverloo, 2014/03/26 21:35:35]

#include "wtf/RefCounted.h"

(IWYU)

[Michael van Ouwerkerk, 2014/03/27 19:15:24]

Done.

+namespace WebCore {
+
+class ExecutionContext;
+class ScriptPromise;

[Peter Beverloo, 2014/03/26 21:35:35]

Can we really forward declare ScriptPromise since it's being returned as a value
in registerPushMessaging()? Surely the size needs to be known?

[Michael van Ouwerkerk, 2014/03/27 19:15:24]

Not sure. How about these precedents?
https://code.google.com/p/chromium/codesearch#search/&q=class%5C%20ScriptProm...

+
+class PushManager FINAL : public RefCounted<PushManager>, public ScriptWrappable {
+public:
+    static PassRefPtr<PushManager> create() { return adoptRef(new PushManager()); }
+    virtual ~PushManager();
+
+    ScriptPromise registerPushMessaging(ExecutionContext*, const String& senderId);
+
+private:
+    PushManager();
+};
+
+} // namespace WebCore
+
+#endif // PushManager_h