Use Promises for screen.lockOrientation().

Source/modules/screen_orientation/LockOrientationCallback.h

Index: Source/modules/screen_orientation/LockOrientationCallback.h
diff --git a/Source/modules/screen_orientation/LockOrientationCallback.h b/Source/modules/screen_orientation/LockOrientationCallback.h
new file mode 100644
index 0000000000000000000000000000000000000000..94f2d83a3d6d436a6394d5ce7292e52ea336ac5a
--- /dev/null
+++ b/Source/modules/screen_orientation/LockOrientationCallback.h
@@ -0,0 +1,37 @@
+// 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 LockOrientationCallback_h
+#define LockOrientationCallback_h
+
+#include "public/platform/WebLockOrientationCallback.h"
+#include "public/platform/WebScreenOrientationType.h"
+#include "wtf/Noncopyable.h"
+#include "wtf/PassRefPtr.h"
+#include "wtf/RefPtr.h"
+
+namespace WebCore {
+
+class ScriptPromiseResolverWithContext;
+
+// LockOrientationCallback is an implementation of WebLockOrientationCallback
+// that will resolve the underlying promise depending on the result passed to
+// the callback.
+class LockOrientationCallback FINAL : public blink::WebLockOrientationCallback {
+public:
+    LockOrientationCallback(PassRefPtr<ScriptPromiseResolverWithContext>);

[Inactive, 2014/05/21 16:01:45]

explicit?

+    virtual ~LockOrientationCallback();
+
+    virtual void onSuccess(unsigned angle, blink::WebScreenOrientationType) OVERRIDE;
+    virtual void onError(ErrorType) OVERRIDE;
+
+private:
+    RefPtr<ScriptPromiseResolverWithContext> m_resolver;
+    WTF_MAKE_NONCOPYABLE(LockOrientationCallback);

[Inactive, 2014/05/21 16:02:50]

nit: I think we usually have this one at the top of the class, right before
public: in Blink.

+};
+
+} // namespace WebCore
+
+#endif // LockOrientationCallback_h
+