[css-flexbox] Correctly implement contain: size on a flex item

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

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 458 matching lines @@
     if (flexLength.isAuto())
         flexLength = isHorizontalFlow() ? child.style()->width() : child.style()->height();
     return flexLength;
 }
 
 LayoutUnit LayoutFlexibleBox::crossAxisExtentForChild(const LayoutBox& child) const
 {
     return isHorizontalFlow() ? child.size().height() : child.size().width();
 }
 
-static inline LayoutUnit constrainedChildIntrinsicContentLogicalHeight(const LayoutBox& child)
+static inline LayoutUnit constrainedChildIntrinsicContentLogicalHeight(const LayoutBox& child, LayoutUnit childIntrinsicContentLogicalHeight)
 {
     // TODO(cbiesinger): scrollbar height?
-    LayoutUnit childIntrinsicContentLogicalHeight = child.intrinsicContentLogicalHeight();
     return child.constrainLogicalHeightByMinMax(childIntrinsicContentLogicalHeight + child.borderAndPaddingLogicalHeight(), childIntrinsicContentLogicalHeight);
 }
 
 LayoutUnit LayoutFlexibleBox::childIntrinsicLogicalHeight(const LayoutBox& child) const
 {
     // This should only be called if the logical height is the cross size
     DCHECK(!hasOrthogonalFlow(child));
-    if (needToStretchChildLogicalHeight(child))
-        return constrainedChildIntrinsicContentLogicalHeight(child);
+    if (needToStretchChildLogicalHeight(child)) {
+        LayoutUnit childIntrinsicContentLogicalHeight;
+        if (!child.styleRef().containsSize())
+            childIntrinsicContentLogicalHeight = child.intrinsicContentLogicalHeight();
+        return constrainedChildIntrinsicContentLogicalHeight(child, childIntrinsicContentLogicalHeight);
+    }
     return child.logicalHeight();
 }
 
 LayoutUnit LayoutFlexibleBox::childIntrinsicLogicalWidth(const LayoutBox& child) const
 {
     // This should only be called if the logical width is the cross size
     DCHECK(hasOrthogonalFlow(child));
     // If our height is auto, make sure that our returned height is unaffected by earlier layouts by
     // returning the max preferred logical width
     if (!crossAxisLengthIsDefinite(child, child.styleRef().logicalWidth()))
@@ skipping 350 matching lines @@
 {
     child.clearOverrideSize();
 
     if (child.isImage() || child.isVideo() || child.isCanvas())
         UseCounter::count(document(), UseCounter::AspectRatioFlexItem);
 
     Length flexBasis = flexBasisForChild(child);
     if (mainAxisLengthIsDefinite(child, flexBasis))
         return std::max(LayoutUnit(), computeMainAxisExtentForChild(child, MainOrPreferredSize, flexBasis));
 
+    if (child.styleRef().containsSize())
+        return LayoutUnit();
+
     LayoutUnit mainAxisExtent;
     if (childFlexBaseSizeRequiresLayout(child)) {
         if (childLayoutType == NeverLayout)
             return LayoutUnit();
 
         if (child.needsLayout() || childLayoutType == ForceLayout || !m_intrinsicSizeAlongMainAxis.contains(&child)) {
             child.forceChildLayout();
             cacheChildMainSize(child);
         }
         mainAxisExtent = m_intrinsicSizeAlongMainAxis.get(&child);
@@ skipping 235 matching lines @@
             childSize = maxExtent;
     }
 
     Length min = isHorizontalFlow() ? child.style()->minWidth() : child.style()->minHeight();
     LayoutUnit minExtent;
     if (min.isSpecifiedOrIntrinsic()) {
         minExtent = computeMainAxisExtentForChild(child, MinSize, min);
         // computeMainAxisExtentForChild can return -1 when the child has a percentage
         // min size, but we have an indefinite size in that axis.
         minExtent = std::max(LayoutUnit(), minExtent);
-    } else if (min.isAuto() && mainAxisOverflowForChild(child) == OverflowVisible && !(isColumnFlow() && child.isFlexibleBox())) {
+    } else if (min.isAuto() && !child.styleRef().containsSize() && mainAxisOverflowForChild(child) == OverflowVisible && !(isColumnFlow() && child.isFlexibleBox())) {
         // TODO(cbiesinger): For now, we do not handle min-height: auto for nested column flexboxes. We need
         // to implement https://drafts.csswg.org/css-flexbox/#intrinsic-sizes before that produces
         // reasonable results. Tracking bug: https://crbug.com/581553
         // css-flexbox section 4.5
         LayoutUnit contentSize = computeMainAxisExtentForChild(child, MinSize, Length(MinContent));
         DCHECK_GE(contentSize, LayoutUnit());
         if (hasAspectRatio(child) && child.intrinsicSize().height() > 0)
             contentSize = adjustChildSizeForAspectRatioCrossAxisMinAndMax(child, contentSize);
         if (maxExtent != -1 && contentSize > maxExtent)
             contentSize = maxExtent;
@@ skipping 793 matching lines @@
             DCHECK(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(*child, newOffset - originalOffset);
         }
     }
 }
 
 } // namespace blink