Update text field 'change' event logic to match to Firefox.

third_party/WebKit/Source/core/html/HTMLTextAreaElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights
  * reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 267 matching lines @@
   // fix it.
   Element* innerEditor = innerEditorElement();
   for (Node& node : NodeTraversal::descendantsOf(*innerEditor)) {
     if (node.isTextNode())
       continue;
     DCHECK(isHTMLBRElement(node));
     DCHECK_EQ(&node, innerEditor->lastChild());
   }
 #endif
   addPlaceholderBreakElementIfNecessary();
-  setChangedSinceLastFormControlChangeEvent(true);
+  setValueBeforeFirstUserEditIfNotSet();
   updateValue();
+  checkIfValueWasReverted(value());
   setNeedsValidityCheck();
   setAutofilled(false);
   updatePlaceholderVisibility();
 
   if (!isFocused())
     return;
 
   // When typing in a textarea, childrenChanged is not called, so we need to
   // force the directionality check.
   calculateAndAdjustDirectionality();
@@ skipping 93 matching lines @@
   normalizedValue.replace("\r\n", "\n");
   normalizedValue.replace('\r', '\n');
 
   // Return early because we don't want to trigger other side effects when the
   // value isn't changing. This is interoperable though the specification
   // doesn't define so.
   // https://github.com/whatwg/html/issues/2412
   if (normalizedValue == value())
     return;
 
+  if (eventBehavior != DispatchNoEvent)
+    setValueBeforeFirstUserEditIfNotSet();
   m_value = normalizedValue;
   setInnerEditorValue(m_value);
   if (eventBehavior == DispatchNoEvent)
     setLastChangeWasNotUserEdit();
+  else
+    checkIfValueWasReverted(m_value);
   updatePlaceholderVisibility();
   setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(
                                               StyleChangeReason::ControlValue));
   m_suggestedValue = String();
   setNeedsValidityCheck();
   if (isFinishedParsingChildren() &&
       selection == TextControlSetValueSelection::kSetSelectionToEnd) {
     // Set the caret to the end of the text value except for initialize.
     unsigned endOfString = m_value.length();
     setSelectionRange(endOfString, endOfString);
   }
 
   notifyFormStateChanged();
   switch (eventBehavior) {
     case DispatchChangeEvent:
       dispatchFormControlChangeEvent();
       break;
 
     case DispatchInputAndChangeEvent:
       dispatchFormControlInputEvent();
       dispatchFormControlChangeEvent();
       break;
 
     case DispatchNoEvent:
-      // We need to update textAsOfLastFormControlChangeEvent for |value| IDL
-      // setter without focus because input-assist features use setValue("...",
-      // DispatchChangeEvent) without setting focus.
-      if (!isFocused())
-        setTextAsOfLastFormControlChangeEvent(normalizedValue);
       break;
   }
 }
 
 String HTMLTextAreaElement::defaultValue() const {
   StringBuilder value;
 
   // Since there may be comments, ignore nodes other than text nodes.
   for (Node* n = firstChild(); n; n = n->nextSibling()) {
     if (n->isTextNode())
@@ skipping 180 matching lines @@
     const Element& source) {
   const HTMLTextAreaElement& sourceElement =
       static_cast<const HTMLTextAreaElement&>(source);
   setValueCommon(sourceElement.value(), DispatchNoEvent,
                  TextControlSetValueSelection::kSetSelectionToEnd);
   m_isDirty = sourceElement.m_isDirty;
   TextControlElement::copyNonAttributePropertiesFromElement(source);
 }
 
 }  // namespace blink