1 files changed, 14 insertions, 0 deletions
diff --git a/widget/nsIBaseWindow.cpp b/widget/nsIBaseWindow.cpp
new file mode 100644
index 0000000000..a9ebdcc860
--- /dev/null
+++ b/widget/nsIBaseWindow.cpp
@@ -0,0 +1,14 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+#include "nsIBaseWindow.h"
+#include "mozilla/LookAndFeel.h"
+
+using namespace mozilla;
+
+CSSToLayoutDeviceScale nsIBaseWindow::UnscaledDevicePixelsPerCSSPixel() {
+  return CSSToLayoutDeviceScale(GetWidgetCSSToDeviceScale() *
+                                LookAndFeel::SystemZoomSettings().mFullZoom);
+}