Fix the inconsistent problem while the content of textNodes is changed

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

Index: third_party/WebKit/Source/core/layout/LayoutText.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutText.cpp b/third_party/WebKit/Source/core/layout/LayoutText.cpp
index a9c752da008b776c0b185fa9edad9f12291e07f9..8f5411e2ca86274528b340436591eda272b33200 100644
--- a/third_party/WebKit/Source/core/layout/LayoutText.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutText.cpp
@@ -34,6 +34,7 @@
 #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"
@@ -209,6 +210,14 @@ void LayoutText::styleDidChange(StyleDifference diff,
   // 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() {
@@ -1654,6 +1663,8 @@ void LayoutText::setText(PassRefPtr<StringImpl> text, bool force) {
   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.
@@ -1664,6 +1675,13 @@ void LayoutText::setText(PassRefPtr<StringImpl> text, bool force) {
         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);
 }