Absolute positioned child with percent should include containing block padding

third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp

 /*
  * Copyright (C) 2004 Zack Rusin <zack@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2011 Sencha, Inc. All rights reserved.
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ skipping 168 matching lines @@
     case CSSPropertyBottom:
         offset = style.bottom();
         opposite = style.top();
         break;
     default:
         return nullptr;
     }
 
     if (offset.hasPercent() && layoutObject && layoutObject->isBox() && layoutObject->isPositioned()) {
         LayoutUnit containingBlockSize = (propertyID == CSSPropertyLeft || propertyID == CSSPropertyRight) ?
-            toLayoutBox(layoutObject)->containingBlockLogicalWidthForContent() :

[esprehn, 2016/04/14 18:43:09]

this is used in multiple other places in CSSValueMapping.cpp, are they wrong
too?

[Deokjin Kim, 2016/04/20 13:42:09]

On PS#7 this change is not needed anymore because we use
containingBlockLogicalWidthForContent(), not
containingBlockLogicalWidthForGetComputedStyle().

+            toLayoutBox(layoutObject)->containingBlockLogicalWidthForGetComputedStyle() :
             toLayoutBox(layoutObject)->containingBlockLogicalHeightForGetComputedStyle();
         return zoomAdjustedPixelValue(valueForLength(offset, containingBlockSize), style);
     }
 
     if (offset.isAuto() && layoutObject) {
         // If the property applies to a positioned element and the resolved value of the display
         // property is not none, the resolved value is the used value.
         if (layoutObject->isInFlowPositioned()) {
             // If e.g. left is auto and right is not auto, then left's computed value is negative right.
             // So we get the opposite length unit and see if it is auto.
@@ skipping 2631 matching lines @@
     case CSSPropertyAll:
         return nullptr;
     default:
         break;
     }
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 } // namespace blink