Generalize and refactor DeviceSensorEvent* architecture to support multi-event type targets.

Source/core/frame/DeviceSingleWindowEventController.h

Index: Source/core/frame/DeviceSingleWindowEventController.h
diff --git a/Source/core/frame/DeviceSingleWindowEventController.h b/Source/core/frame/DeviceSingleWindowEventController.h
new file mode 100644
index 0000000000000000000000000000000000000000..86e757529217d5f24f7c66fb839f6a70f39dc804
--- /dev/null
+++ b/Source/core/frame/DeviceSingleWindowEventController.h
@@ -0,0 +1,44 @@
+// 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 DeviceSingleWindowEventController_h
+#define DeviceSingleWindowEventController_h
+
+#include "core/frame/DOMWindowLifecycleObserver.h"
+#include "core/frame/DeviceEventControllerBase.h"
+#include "platform/heap/Handle.h"
+
+namespace WebCore {
+
+class Document;
+class Event;
+
+class DeviceSingleWindowEventController : public DeviceEventControllerBase, public DOMWindowLifecycleObserver {
+public:
+    // Inherited from DeviceEventControllerBase.
+    virtual void didUpdateData() OVERRIDE;
+
+    // Inherited from DOMWindowLifecycleObserver.
+    virtual void didAddEventListener(DOMWindow*, const AtomicString&) OVERRIDE;
+    virtual void didRemoveEventListener(DOMWindow*, const AtomicString&) OVERRIDE;
+    virtual void didRemoveAllEventListeners(DOMWindow*) OVERRIDE;
+
+protected:
+    explicit DeviceSingleWindowEventController(Document&);
+    virtual ~DeviceSingleWindowEventController();
+
+    void dispatchDeviceEvent(const PassRefPtrWillBeRawPtr<Event>);
+
+    virtual PassRefPtrWillBeRawPtr<Event> lastEvent() const = 0;
+    virtual const AtomicString& eventTypeName() const = 0;
+    virtual bool isNullEvent(Event*) const = 0;
+
+private:
+    bool m_needsCheckingNullEvents;
+    Document& m_document;
+};
+
+} // namespace WebCore
+
+#endif // DeviceSingleWindowEventController_h