[css-flexbox] Don't over-invalidate flex items

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 845 matching lines @@
     Vector<LineContext> lineContexts;
     OrderedFlexItemList orderedChildren;
     LayoutUnit sumFlexBaseSize;
     double totalFlexGrow;
     double totalFlexShrink;
     double totalWeightedFlexShrink;
     LayoutUnit sumHypotheticalMainSize;
 
     PaintLayerScrollableArea::PreventRelayoutScope preventRelayoutScope(layoutScope);
 
-    dirtyForLayoutFromPercentageHeightDescendants(layoutScope);
-
     m_orderIterator.first();
     LayoutUnit crossAxisOffset = flowAwareBorderBefore() + flowAwarePaddingBefore();
     while (computeNextFlexLine(orderedChildren, sumFlexBaseSize, totalFlexGrow, totalFlexShrink, totalWeightedFlexShrink, sumHypotheticalMainSize, relayoutChildren)) {
         LayoutUnit containerMainInnerSize = mainAxisContentExtent(sumHypotheticalMainSize);
         // availableFreeSpace is the initial amount of free space in this flexbox.
         // remainingFreeSpace starts out at the same value but as we place and lay out
         // flex items we subtract from it. Note that both values can be negative.
         LayoutUnit remainingFreeSpace = containerMainInnerSize - sumFlexBaseSize;
         FlexSign flexSign = (sumHypotheticalMainSize < containerMainInnerSize) ? PositiveFlexibility : NegativeFlexibility;
         freezeInflexibleItems(flexSign, orderedChildren, remainingFreeSpace, totalFlexGrow, totalFlexShrink, totalWeightedFlexShrink);
@@ skipping 718 matching lines @@
 
         LayoutUnit childPreferredSize = flexItem.flexedContentSize + mainAxisBorderAndPaddingExtentForChild(*child);
         setOverrideMainAxisSizeForChild(*child, childPreferredSize);
         if (childPreferredSize != mainAxisExtentForChild(*child)) {
             child->setChildNeedsLayout(MarkOnlyThis);
         } else {
             // To avoid double applying margin changes in updateAutoMarginsInCrossAxis, we reset the margins here.
             resetAutoMarginsAndLogicalTopInCrossAxis(*child);
         }
         // We may have already forced relayout for orthogonal flowing children in computeInnerFlexBaseSizeForChild.
-        bool forceChildRelayout = relayoutChildren && !childFlexBaseSizeRequiresLayout(*child);
-        if (child->isLayoutBlock() && toLayoutBlock(*child).hasPercentHeightDescendants() && m_relaidOutChildren.contains(child)) {
+        bool forceChildRelayout = relayoutChildren && !m_relaidOutChildren.contains(child);
+        if (child->isLayoutBlock() && toLayoutBlock(*child).hasPercentHeightDescendants()) {
             // Have to force another relayout even though the child is sized correctly, because
             // its descendants are not sized correctly yet. Our previous layout of the child was
             // done without an override height set. So, redo it here.
             forceChildRelayout = true;
         }
         updateBlockChildDirtyBitsBeforeLayout(forceChildRelayout, *child);
         if (!child->needsLayout())
             child->markForPaginationRelayoutIfNeeded(layoutScope);
         if (child->needsLayout())
             m_relaidOutChildren.add(child);
@@ skipping 267 matching lines @@
             ASSERT(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(*child, newOffset - originalOffset);
         }
     }
 }
 
 } // namespace blink