diff -r 000000000000 -r 6474c204b198 layout/base/nsPresState.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/base/nsPresState.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,90 @@
+/* -*- 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/. */
+
+/*
+ * a piece of state that is stored in session history when the document
+ * is not
+ */
+
+#ifndef nsPresState_h_
+#define nsPresState_h_
+
+#include "nsPoint.h"
+#include "gfxPoint.h"
+#include "nsAutoPtr.h"
+
+class nsPresState
+{
+public:
+  nsPresState()
+    : mContentData(nullptr)
+    , mScrollState(0, 0)
+    , mResolution(1.0, 1.0)
+    , mDisabledSet(false)
+    , mDisabled(false)
+  {}
+
+  void SetScrollState(const nsPoint& aState)
+  {
+    mScrollState = aState;
+  }
+
+  nsPoint GetScrollState() const
+  {
+    return mScrollState;
+  }
+
+  void SetResolution(const gfxSize& aSize)
+  {
+    mResolution = aSize;
+  }
+
+  gfxSize GetResolution() const
+  {
+    return mResolution;
+  }
+
+  void ClearNonScrollState()
+  {
+    mContentData = nullptr;
+    mDisabledSet = false;
+  }
+
+  bool GetDisabled() const
+  {
+    return mDisabled;
+  }
+
+  void SetDisabled(bool aDisabled)
+  {
+    mDisabled = aDisabled;
+    mDisabledSet = true;
+  }
+
+  bool IsDisabledSet() const
+  {
+    return mDisabledSet;
+  }
+
+  nsISupports* GetStateProperty() const
+  {
+    return mContentData;
+  }
+
+  void SetStateProperty(nsISupports *aProperty)
+  {
+    mContentData = aProperty;
+  }
+
+// MEMBER VARIABLES
+protected:
+  nsCOMPtr<nsISupports> mContentData;
+  nsPoint mScrollState;
+  gfxSize mResolution;
+  bool mDisabledSet;
+  bool mDisabled;
+};
+
+#endif /* nsPresState_h_ */