Fix the inconsistent problem while the content of textNodes is changed

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

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 16 matching lines @@
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/Text.h"
 #include "core/editing/VisiblePosition.h"
 #include "core/editing/iterators/TextIterator.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutTableCell.h"
 #include "core/layout/LayoutTextCombine.h"
 #include "core/layout/LayoutView.h"
+#include "core/layout/TextAutosizer.h"
 #include "core/layout/api/LineLayoutBox.h"
 #include "core/layout/line/AbstractInlineTextBox.h"
 #include "core/layout/line/EllipsisBox.h"
 #include "core/layout/line/GlyphOverflow.h"
 #include "core/layout/line/InlineTextBox.h"
 #include "platform/fonts/CharacterRange.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/text/BidiResolver.h"
 #include "platform/text/Character.h"
 #include "platform/text/Hyphenation.h"
@@ skipping 155 matching lines @@
   const ComputedStyle& newStyle = styleRef();
   ETextTransform oldTransform = oldStyle ? oldStyle->textTransform() : TTNONE;
   ETextSecurity oldSecurity = oldStyle ? oldStyle->textSecurity() : TSNONE;
   if (oldTransform != newStyle.textTransform() ||
       oldSecurity != newStyle.textSecurity())
     transformText();
 
   // This is an optimization that kicks off font load before layout.
   if (!text().containsOnlyWhitespace())
     newStyle.font().willUseFontData(text());
+
+  TextAutosizer* textAutosizer = document().textAutosizer();
+  unsigned newAddedTextLength = text().stripWhiteSpace().length();
+  if (!oldStyle && textAutosizer && newAddedTextLength > 0 &&

[skobes, 2016/11/09 03:11:39]

Why do we check !oldStyle here?

[cathiechentx, 2016/11/09 12:58:46]

We only keep a count of new created/added text. "!oldStyle" represents that this
layouttext is new created. 

+      newStyle.textAutosizingFingerPrint() != 0) {
+    textAutosizer->textAutosizingNewTextAdded(
+        newStyle.textAutosizingFingerPrint(), newAddedTextLength);

[skobes, 2016/11/09 03:11:39]

Can we just pass the LayoutText* and have TextAutosizer retrieve these?

[cathiechentx, 2016/11/09 12:58:46]

yes, passing the LayoutText* is more elegant, and it could work in
styleDidChange(), but in setText() we like to count the increase part of the
text. So newAddedTextLength is more precise.

+  }
 }
 
 void LayoutText::removeAndDestroyTextBoxes() {
   if (!documentBeingDestroyed()) {
     if (firstTextBox()) {
       if (isBR()) {
         RootInlineBox* next = firstTextBox()->root().nextRootBox();
         if (next)
           next->markDirty();
       }
@@ skipping 1425 matching lines @@
     secureTextTimer->invalidate();
   }
 }
 
 void LayoutText::setText(PassRefPtr<StringImpl> text, bool force) {
   ASSERT(text);
 
   if (!force && equal(m_text.impl(), text.get()))
     return;
 
+  int newAddedTextLength =
+      text->stripWhiteSpace()->length() - m_text.stripWhiteSpace().length();
   setTextInternal(std::move(text));
   // If preferredLogicalWidthsDirty() of an orphan child is true,
   // LayoutObjectChildList::insertChildNode() fails to set true to owner.
   // To avoid that, we call setNeedsLayoutAndPrefWidthsRecalc() only if this
   // LayoutText has parent.
   if (parent())
     setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation(
         LayoutInvalidationReason::TextChanged);
   m_knownToHaveNoOverflowAndNoFallbackFonts = false;
 
+  TextAutosizer* textAutosizer = document().textAutosizer();
+  if (textAutosizer && style() && newAddedTextLength > 0 &&
+      style()->textAutosizingFingerPrint() != 0) {
+    textAutosizer->textAutosizingNewTextAdded(
+        style()->textAutosizingFingerPrint(), (unsigned)newAddedTextLength);
+  }
+
   if (AXObjectCache* cache = document().existingAXObjectCache())
     cache->textChanged(this);
 }
 
 void LayoutText::dirtyOrDeleteLineBoxesIfNeeded(bool fullLayout) {
   if (fullLayout)
     deleteTextBoxes();
   else if (!m_linesDirty)
     dirtyLineBoxes();
   m_linesDirty = false;
@@ skipping 296 matching lines @@
   LayoutRect rect = LayoutRect(
       IntRect(firstRunX(), firstRunY(), linesBox.width(), linesBox.height()));
   LayoutBlock* block = containingBlock();
   if (block && hasTextBoxes())
     block->adjustChildDebugRect(rect);
 
   return rect;
 }
 
 }  // namespace blink