Screen Orientation API: cleanup, simplify and fix implementation.

public/platform/WebScreenOrientationLockType.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 WebScreenOrientationLockType_h
+#define WebScreenOrientationLockType_h
+
+namespace blink {
+
+enum WebScreenOrientationLockType {
+    WebScreenOrientationLockDefault = 0, // Equivalent to unlock.
+    WebScreenOrientationLockPortraitPrimary,
+    WebScreenOrientationLockPortraitSecondary,
+    WebScreenOrientationLockLandscapePrimary,
+    WebScreenOrientationLockLandscapeSecondary,
+    WebScreenOrientationLockAny,
+    WebScreenOrientationLockLandscape,
+    WebScreenOrientationLockPortrait
+};
+
+} // namespace blink
+
+#endif // WebScreenOrientationLockType_h