Stay put at the top of the current page when inserting a forced break.

third_party/WebKit/Source/core/layout/LayoutBlock.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 362 matching lines @@
 
     // End helper functions and structs used by layoutBlockChildren.
 
     void removeFromGlobalMaps();
     bool widthAvailableToChildrenHasChanged();
 
 protected:
     bool isPageLogicalHeightKnown(LayoutUnit logicalOffset) const { return pageLogicalHeightForOffset(logicalOffset); }
 
     // Returns the logical offset at the top of the next page, for a given offset.
-    //
-    // If the given offset is at a page boundary, using AssociateWithLatterPage as PageBoundaryRule
-    // will move us one page ahead (since the offset is at the top of the "current" page). Using
-    // AssociateWithFormerPage instead will keep us where we are (since the offset is at the bottom
-    // of the "current" page, which is exactly the same offset as the top offset on the next page).
-    //
-    // For a page height of 800px, AssociateWithLatterPage will return 1600 if the value passed in
-    // is 800. AssociateWithFormerPage will simply return 800.
-    LayoutUnit nextPageLogicalTop(LayoutUnit logicalOffset, PageBoundaryRule) const;
+    LayoutUnit nextPageLogicalTop(LayoutUnit logicalOffset) const;
 
     // Paginated content inside this block was laid out.
     // |logicalBottomOffsetAfterPagination| is the logical bottom offset of the child content after
     // applying any forced or unforced breaks as needed.
     void paginatedContentWasLaidOut(LayoutUnit logicalBottomOffsetAfterPagination);
 
     // Adjust from painting offsets to the local coords of this layoutObject
     void offsetForContents(LayoutPoint&) const;
 
     PositionWithAffinity positionForPointRespectingEditingBoundaries(LineLayoutBox child, const LayoutPoint& pointInParentCoordinates);
@@ skipping 27 matching lines @@
     // TODO(lunalu): Temporary in order to ensure compatibility with existing layout test
     // results.
     virtual void adjustChildDebugRect(LayoutRect&) const {}
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlock, isLayoutBlock());
 
 } // namespace blink
 
 #endif // LayoutBlock_h