diff -r 000000000000 -r 6474c204b198 layout/generic/nsIPageSequenceFrame.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/generic/nsIPageSequenceFrame.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,62 @@
+/* -*- 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/. */
+#ifndef nsIPageSequenceFrame_h___
+#define nsIPageSequenceFrame_h___
+
+#include "nsQueryFrame.h"
+#include "nsCoord.h"
+
+class nsPresContext;
+class nsIPrintSettings;
+class nsITimerCallback;
+
+/**
+ * Interface for accessing special capabilities of the page sequence frame.
+ *
+ * Today all that exists are member functions for printing.
+ */
+class nsIPageSequenceFrame : public nsQueryFrame
+{
+public:
+  NS_DECL_QUERYFRAME_TARGET(nsIPageSequenceFrame)
+
+  /**
+   * Print the set of pages.
+   *
+   * @param   aPrintOptions options for printing
+   * @param   aStatusCallback interface that the client provides to receive
+   *            progress notifications. Can be nullptr
+   * @return  NS_OK if successful
+   *          NS_ERROR_ABORT if the client cancels printing using the callback
+   *            interface
+   *          NS_ERROR_INVALID_ARG if printing a range of pages (not all pages)
+   *            and the start page is greater than the total number of pages
+   *          NS_ERROR_FAILURE if there is an error
+   */
+  NS_IMETHOD StartPrint(nsPresContext*    aPresContext,
+                        nsIPrintSettings* aPrintOptions,
+                        const nsAString&  aDocTitle,
+                        const nsAString&  aDocURL) = 0;
+
+  NS_IMETHOD PrePrintNextPage(nsITimerCallback* aCallback, bool* aDone) = 0;
+  NS_IMETHOD PrintNextPage() = 0;
+  NS_IMETHOD ResetPrintCanvasList() = 0;
+  NS_IMETHOD GetCurrentPageNum(int32_t* aPageNum) = 0;
+  NS_IMETHOD GetNumPages(int32_t* aNumPages) = 0;
+  NS_IMETHOD IsDoingPrintRange(bool* aDoing) = 0;
+  NS_IMETHOD GetPrintRange(int32_t* aFromPage, int32_t* aToPage) = 0;
+
+  NS_IMETHOD DoPageEnd() = 0;
+  NS_IMETHOD SetSelectionHeight(nscoord aYOffset, nscoord aHeight) = 0;
+
+  NS_IMETHOD SetTotalNumPages(int32_t aTotal) = 0;
+
+  // For Shrink To Fit
+  NS_IMETHOD GetSTFPercent(float& aSTFPercent) = 0;
+};
+
+#endif /* nsIPageSequenceFrame_h___ */
+
+