Add grid/flex layout support for <fieldset>

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

 /*
  * Copyright (C) 2013 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 1145 matching lines @@
     }
 }
 
 void LayoutBlockFlow::layoutBlockChildren(bool relayoutChildren, SubtreeLayoutScope& layoutScope, LayoutUnit beforeEdge, LayoutUnit afterEdge)
 {
     dirtyForLayoutFromPercentageHeightDescendants(layoutScope);
 
     BlockChildrenLayoutInfo layoutInfo(this, beforeEdge, afterEdge);
     MarginInfo& marginInfo = layoutInfo.marginInfo();
 
-    // Fieldsets need to find their legend and position it inside the border of the object.
-    // The legend then gets skipped during normal layout. The same is true for ruby text.
-    // It doesn't get included in the normal layout process but is instead skipped.
     LayoutObject* childToExclude = layoutSpecialExcludedChild(relayoutChildren, layoutScope);
 
     LayoutBox* next = firstChildBox();
     LayoutBox* lastNormalFlowChild = nullptr;
 
     while (next) {
         LayoutBox* child = next;
         next = child->nextSiblingBox();
 
         child->setMayNeedPaintInvalidation();
 
         if (childToExclude == child)
-            continue; // Skip this child, since it will be positioned by the specialized subclass (fieldsets and ruby runs).
+            continue; // Skip this child, since it will be positioned by the specialized subclass (ruby runs).
 
         updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, *child);
 
         if (child->isOutOfFlowPositioned()) {
             child->containingBlock()->insertPositionedObject(child);
             adjustPositionedBlock(*child, layoutInfo);
             continue;
         }
         if (child->isFloating()) {
             insertFloatingObject(*child);
@@ skipping 1211 matching lines @@
             newBlock->addChild(newChild);
             newBlock->reparentSubsequentFloatingOrOutOfFlowSiblings();
             return;
         }
     }
 
     // Skip the LayoutBlock override, since that one deals with anonymous child insertion in a way
     // that isn't sufficient for us, and can only cause trouble at this point.
     LayoutBox::addChild(newChild, beforeChild);
 
-    if (madeBoxesNonInline && parent() && isAnonymousBlock() && parent()->isLayoutBlock()) {
+    if (madeBoxesNonInline && parent() && isAnonymousBlock() && parent()->isLayoutBlock() && !parent()->createsAnonymousWrapper()) {
         toLayoutBlock(parent())->removeLeftoverAnonymousBlock(this);
         // |this| may be dead now.
     }
 }
 
 static bool isMergeableAnonymousBlock(const LayoutBlockFlow* block)
 {
     return block->isAnonymousBlock() && !block->continuation() && !block->beingDestroyed() && !block->isRubyRun() && !block->isRubyBase();
 }
 
@@ skipping 1057 matching lines @@
     }
 
     if (type == NoFlowThread || multiColumnFlowThread())
         return;
 
     // Ruby elements manage child insertion in a special way, and would mess up insertion of the
     // flow thread. The flow thread needs to be a direct child of the multicol block (|this|).
     if (isRuby())
         return;
 
-    // Fieldsets look for a legend special child (layoutSpecialExcludedChild()). We currently only
-    // support one special child per layout object, and the flow thread would make for a second one.
-    if (isFieldset())
-        return;
-
     // Form controls are replaced content, and are therefore not supposed to support multicol.
     if (isFileUploadControl() || isTextControl() || isListBox())
         return;
 
     LayoutMultiColumnFlowThread* flowThread = createMultiColumnFlowThread(type);
     addChild(flowThread);
 
     // Check that addChild() put the flow thread as a direct child, and didn't do fancy things.
     ASSERT(flowThread->parent() == this);
 
@@ skipping 247 matching lines @@
 
     return LayoutBlock::invalidatePaintIfNeeded(paintInvalidationState);
 }
 
 void LayoutBlockFlow::invalidateDisplayItemClients(PaintInvalidationReason invalidationReason) const
 {
     BlockFlowPaintInvalidator(*this).invalidateDisplayItemClients(invalidationReason);
 }
 
 } // namespace blink