Add initial Blink-side support for the Screen Orientation API

Source/modules/screen_orientation/ScreenOrientationController.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 ScreenOrientationController_h
+#define ScreenOrientationController_h
+
+#include "core/page/Page.h"
+#include "modules/screen_orientation/ScreenOrientation.h"
+#include "wtf/PassRefPtr.h"
+
+namespace WebCore {
+
+class ScreenOrientationClient;
+
+class ScreenOrientationController : public Supplement<Page> {
+    WTF_MAKE_NONCOPYABLE(ScreenOrientationController);
+public:
+    static PassOwnPtr<ScreenOrientationController> create(ScreenOrientationClient*);
+
+    void addObserver(ScreenOrientation*);
+    void removeObserver(ScreenOrientation*);
+
+    static const char* supplementName();
+    static ScreenOrientationController* from(Page* page) { return static_cast<ScreenOrientationController*>(Supplement<Page>::from(page, supplementName())); }
+    static ScreenOrientationClient* clientFrom(Page*);
+
+    void orientationChanged(ScreenOrientationValue);
+    ScreenOrientationValue orientation() const { return m_orientation; }
+
+    void setClientForTest(ScreenOrientationClient*);
+    bool hasClientForTest() { return m_hasClientForTest; }
+    ScreenOrientationClient* client() { return m_client; }
+
+private:
+    explicit ScreenOrientationController(ScreenOrientationClient*);
+
+    ScreenOrientationClient* m_client;
+    ScreenOrientationValue m_orientation;
+    bool m_hasClientForTest;
+
+    typedef HashSet<ScreenOrientation*> ObserversSet;
+    // All observers; both those requesting high accuracy and those not.
+    ObserversSet m_observers;
+};
+
+void provideScreenOrientation(Page*, ScreenOrientationClient*);
+
+} // namespace WebCore
+
+#endif // ScreenOrientationController_h