Remove branch on childNeedsDistributionRecalc

third_party/WebKit/Source/core/dom/Text.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
  * reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 236 matching lines @@
       parent.isLayoutTableCol() || parent.isFrameSet() ||
       parent.isFlexibleBox() || parent.isLayoutGrid() || parent.isSVGRoot() ||
       parent.isSVGContainer() || parent.isSVGImage() || parent.isSVGShape()) {
     return false;
   }
   return true;
 }
 
 bool Text::textLayoutObjectIsNeeded(const ComputedStyle& style,
                                     const LayoutObject& parent) const {
+  DCHECK(!document().childNeedsDistributionRecalc());
+
   if (!parent.canHaveChildren())
     return false;
 
   if (isEditingText())
     return true;
 
   if (!length())
     return false;
 
   if (style.display() == EDisplay::None)
     return false;
 
   if (!containsOnlyWhitespace())
     return true;
 
   if (!canHaveWhitespaceChildren(parent))
     return false;
 
   // pre-wrap in SVG never makes layoutObject.
   if (style.whiteSpace() == EWhiteSpace::kPreWrap && parent.isSVG())
     return false;
 
   // pre/pre-wrap/pre-line always make layoutObjects.
   if (style.preserveNewline())
     return true;
 
-  // childNeedsDistributionRecalc() here is rare, only happens JS calling
-  // surroundContents() etc. from DOMNodeInsertedIntoDocument etc.
-  if (document().childNeedsDistributionRecalc())
-    return true;
-
   // Avoiding creation of a layoutObject for the text node is a non-essential
   // memory optimization.  So to avoid blowing up on very wide DOMs, we limit
   // the number of siblings to visit.
   unsigned maxSiblingsToVisit = 50;
 
   const LayoutObject* prev =
       LayoutTreeBuilderTraversal::previousSiblingLayoutObject(
           *this, maxSiblingsToVisit);
   if (prev && prev->isBR())  // <span><br/> <br/></span>
     return false;
@@ skipping 118 matching lines @@
   return false;
 }
 
 // Passing both |textNode| and its layout object because repeated calls to
 // |Node::layoutObject()| are discouraged.
 static bool shouldUpdateLayoutByReattaching(const Text& textNode,
                                             LayoutText* textLayoutObject) {
   DCHECK_EQ(textNode.layoutObject(), textLayoutObject);
   if (!textLayoutObject)
     return true;
-  if (!textNode.textLayoutObjectIsNeeded(*textLayoutObject->style(),
-                                         *textLayoutObject->parent()))
+  // In genenral we do not want to branch on lifecycle states such as
+  // |childNeedsDistributionRecalc|, but this code tries to figure out if we can
+  // use an optimized code path that avoids reattach.
+  if (!textNode.document().childNeedsDistributionRecalc() &&
+      !textNode.textLayoutObjectIsNeeded(*textLayoutObject->style(),
+                                         *textLayoutObject->parent())) {

[rune, 2017/02/09 09:16:48]

genenral -> general

     return true;
+  }
   if (textLayoutObject->isTextFragment()) {
     // Changes of |textNode| may change first letter part, so we should
     // reattach.
     return toLayoutTextFragment(textLayoutObject)->firstLetterPseudoElement();
   }
   return false;
 }
 
 void Text::updateTextLayoutObject(unsigned offsetOfReplacedData,
                                   unsigned lengthOfReplacedData) {
@@ skipping 10 matching lines @@
 
 Text* Text::cloneWithData(const String& data) {
   return create(document(), data);
 }
 
 DEFINE_TRACE(Text) {
   CharacterData::trace(visitor);
 }
 
 }  // namespace blink