Do not dispatch change event when pressing spin button for input type=datetime

Source/core/html/shadow/DateTimeFieldElement.cpp

 /*
  * Copyright (C) 2012 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:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 40 matching lines @@
     , m_fieldOwner(&fieldOwner)
 {
 }
 
 void DateTimeFieldElement::defaultEventHandler(Event* event)
 {
     if (event->isKeyboardEvent()) {
         KeyboardEvent* keyboardEvent = toKeyboardEvent(event);
         if (!isDisabled() && !isFieldOwnerDisabled() && !isFieldOwnerReadOnly()) {
             handleKeyboardEvent(keyboardEvent);
-            if (keyboardEvent->defaultHandled())
+            if (keyboardEvent->defaultHandled()) {
+                if (m_fieldOwner)
+                    m_fieldOwner->fieldDidChangeValueByKeyboard();
                 return;
+            }
         }
         defaultKeyboardEventHandler(keyboardEvent);
+        if (m_fieldOwner)
+            m_fieldOwner->fieldDidChangeValueByKeyboard();
         if (keyboardEvent->defaultHandled())
             return;
     }
 
     HTMLElement::defaultEventHandler(event);
 }
 
 void DateTimeFieldElement::defaultKeyboardEventHandler(KeyboardEvent* keyboardEvent)
 {
     if (keyboardEvent->type() != EventTypeNames::keydown)
@@ skipping 146 matching lines @@
 }
 
 int DateTimeFieldElement::valueForARIAValueNow() const
 {
     return valueAsInteger();
 }
 
 } // namespace WebCore
 
 #endif