diff -r 000000000000 -r 6474c204b198 widget/cocoa/nsScreenCocoa.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/cocoa/nsScreenCocoa.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsScreenCocoa_h_
+#define nsScreenCocoa_h_
+
+#import <Cocoa/Cocoa.h>
+
+#include "nsBaseScreen.h"
+
+class nsScreenCocoa : public nsBaseScreen
+{
+public:
+    nsScreenCocoa (NSScreen *screen);
+    ~nsScreenCocoa ();
+
+    NS_IMETHOD GetRect(int32_t* aLeft, int32_t* aTop, int32_t* aWidth, int32_t* aHeight);
+    NS_IMETHOD GetAvailRect(int32_t* aLeft, int32_t* aTop, int32_t* aWidth, int32_t* aHeight);
+    NS_IMETHOD GetRectDisplayPix(int32_t* aLeft, int32_t* aTop, int32_t* aWidth, int32_t* aHeight);
+    NS_IMETHOD GetAvailRectDisplayPix(int32_t* aLeft, int32_t* aTop, int32_t* aWidth, int32_t* aHeight);
+    NS_IMETHOD GetPixelDepth(int32_t* aPixelDepth);
+    NS_IMETHOD GetColorDepth(int32_t* aColorDepth);
+    NS_IMETHOD GetContentsScaleFactor(double* aContentsScaleFactor);
+
+    NSScreen *CocoaScreen() { return mScreen; }
+
+private:
+    CGFloat BackingScaleFactor();
+
+    NSScreen *mScreen;
+};
+
+#endif // nsScreenCocoa_h_