LayoutBlock::removeChild() override no longer needed.

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 2290 matching lines @@
 
 void LayoutBlockFlow::removeChild(LayoutObject* oldChild)
 {
     // No need to waste time in merging or removing empty anonymous blocks.
     // We can just bail out if our document is getting destroyed.
     if (documentBeingDestroyed()) {
         LayoutBox::removeChild(oldChild);
         return;
     }
 
+    // If this child is a block, and if our previous and next siblings are
+    // both anonymous blocks with inline content, then we can go ahead and
+    // fold the inline content back together.
+    LayoutObject* prev = oldChild->previousSibling();
+    LayoutObject* next = oldChild->nextSibling();
+    bool mergedAnonymousBlocks = false;
+    if (prev && next && !oldChild->isInline() && !oldChild->virtualContinuation() && prev->isLayoutBlockFlow() && next->isLayoutBlockFlow()) {
+        if (toLayoutBlockFlow(prev)->mergeSiblingContiguousAnonymousBlock(toLayoutBlockFlow(next))) {
+            mergedAnonymousBlocks = true;
+            next = nullptr;
+        }
+    }
+
     LayoutBlock::removeChild(oldChild);
+
+    LayoutObject* child = prev ? prev : next;
+    if (mergedAnonymousBlocks && child && !child->previousSibling() && !child->nextSibling()) {
+        // The removal has knocked us down to containing only a single anonymous
+        // box.  We can go ahead and pull the content right back up into our
+        // box.
+        collapseAnonymousBlockChild(this, toLayoutBlock(child));
+    }
+
     if (!firstChild()) {
         // If this was our last child be sure to clear out our line boxes.
         if (childrenInline())
             deleteLineBoxTree();
 
         // If we are an empty anonymous block in the continuation chain,
         // we need to remove ourself and fix the continuation chain.
         if (!beingDestroyed() && isAnonymousBlockContinuation() && !oldChild->isListMarker()) {
             LayoutObject* containingBlockIgnoringAnonymous = containingBlock();
             while (containingBlockIgnoringAnonymous && containingBlockIgnoringAnonymous->isAnonymous())
@@ skipping 1163 matching lines @@
             if (!rect.isEmpty())
                 rects.append(rect);
         }
     }
 
     if (inlineElementContinuation)
         inlineElementContinuation->addOutlineRects(rects, additionalOffset + (inlineElementContinuation->containingBlock()->location() - location()), includeBlockOverflows);
 }
 
 } // namespace blink