Don't let rounding prematurely influence document size when printing

third_party/WebKit/Source/core/layout/LayoutView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 815 matching lines @@
     if (hasOverflowClip())
         excludeScrollbars(rect, overlayScrollbarClipBehavior);
 
     return rect;
 }
 
 IntRect LayoutView::documentRect() const
 {
     LayoutRect overflowRect(layoutOverflowRect());
     flipForWritingMode(overflowRect);
-    return pixelSnappedIntRect(overflowRect);
+    return IntRect(roundedIntPoint(overflowRect.location()), IntSize(
+        floorToInt(overflowRect.width()),

[eae, 2016/07/12 22:26:39]

This is incorrect. We do not floor sizes, we pixel snap them.

[rhogan, 2016/07/13 18:27:13]

Yes, this is wrong.

+        floorToInt(overflowRect.height())));
 }
 
 bool LayoutView::rootBackgroundIsEntirelyFixed() const
 {
     return style()->hasEntirelyFixedBackground();
 }
 
 LayoutRect LayoutView::backgroundRect(LayoutBox* backgroundLayoutObject) const
 {
     return LayoutRect(documentRect());
@@ skipping 156 matching lines @@
     // of this override. All frame scrolling should be handled by
     // ViewportScrollCallback.
 
     if (!frameView())
         return ScrollResult(false, false, delta.width(), delta.height());
 
     return frameView()->getScrollableArea()->userScroll(granularity, delta);
 }
 
 } // namespace blink