Cleanup friends of LayoutObject

Source/core/layout/LayoutBlock.cpp

Index: Source/core/layout/LayoutBlock.cpp
diff --git a/Source/core/layout/LayoutBlock.cpp b/Source/core/layout/LayoutBlock.cpp
index 116c979367c9b7c7fc0eb820d6eeff761531ee70..5ed9d6a3ba35c1c6af96047ada0cc1525352990c 100644
--- a/Source/core/layout/LayoutBlock.cpp
+++ b/Source/core/layout/LayoutBlock.cpp
@@ -562,14 +562,14 @@ void LayoutBlock::promoteAllChildrenAndInsertAfter()
     LayoutBlock* parent = toLayoutBlock(this->parent());
     LayoutObject* nextSiblingOfPromotees = nextSibling();
     for (LayoutObject* o = firstPromotee; o; o = o->nextSibling())
-        o->setParent(parent);
+        DangerousLayoutTreeMutator(*o).setParent(parent);
     children()->setFirstChild(nullptr);
     children()->setLastChild(nullptr);
-    firstPromotee->setPreviousSibling(this);
-    setNextSibling(firstPromotee);
-    lastPromotee->setNextSibling(nextSiblingOfPromotees);
+    DangerousLayoutTreeMutator(*firstPromotee).setPreviousSibling(this);
+    DangerousLayoutTreeMutator(*this).setNextSibling(firstPromotee);
+    DangerousLayoutTreeMutator(*lastPromotee).setNextSibling(nextSiblingOfPromotees);
     if (nextSiblingOfPromotees)
-        nextSiblingOfPromotees->setPreviousSibling(lastPromotee);
+        DangerousLayoutTreeMutator(*nextSiblingOfPromotees).setPreviousSibling(lastPromotee);

[esprehn, 2015/08/21 21:20:32]

Instead of having all methods I'd prefer it only had insertBefore() and
setParent() and we moved this tree mutation operation into the
LayoutObjectChildList or the DangerousLayoutTreeMutator.

setParent() should also ASSERT that nextSibling() and previousSibling() are
nullptr.

[Xianzhu, 2015/08/21 22:52:19]

Thanks for the finding. Actually I didn't look into the real logic here.

Changed the whole function body to moveAllChildrenTo(parent(), nextSibling()).

     if (parent->children()->lastChild() == this)
         parent->children()->setLastChild(lastPromotee);
 }
@@ -589,7 +589,7 @@ void LayoutBlock::removeLeftoverAnonymousBlock(LayoutBlock* child)
     child->promoteAllChildrenAndInsertAfter();
 
     // Remove all the information in the flow thread associated with the leftover anonymous block.
-    child->removeFromLayoutFlowThread();
+    DangerousLayoutTreeMutator(*child).removeFromLayoutFlowThread();

[esprehn, 2015/08/21 21:20:31]

I think I would just make removeFromLayoutFlowThread public.

[Xianzhu, 2015/08/21 22:52:19]

Done.

 
     // LayoutGrid keeps track of its children, we must notify it about changes in the tree.
     if (child->parent()->isLayoutGrid())
@@ -2778,7 +2778,7 @@ static bool recalcNormalFlowChildOverflowIfNeeded(LayoutObject* layoutObject)
 bool LayoutBlock::recalcChildOverflowAfterStyleChange()
 {
     ASSERT(childNeedsOverflowRecalcAfterStyleChange());
-    setChildNeedsOverflowRecalcAfterStyleChange(false);
+    clearChildNeedsOverflowRecalcAfterStyleChange();
 
     bool childrenOverflowChanged = false;
 
@@ -2834,7 +2834,7 @@ bool LayoutBlock::recalcOverflowAfterStyleChange()
     if (!selfNeedsOverflowRecalcAfterStyleChange() && !childrenOverflowChanged)
         return false;
 
-    setSelfNeedsOverflowRecalcAfterStyleChange(false);
+    clearSelfNeedsOverflowRecalcAfterStyleChange();
     // If the current block needs layout, overflow will be recalculated during
     // layout time anyway. We can safely exit here.
     if (needsLayout())