Revert of Update of change event for input type number (https://codereview.chromium.org/128133002/)

Source/core/html/forms/TextFieldInputType.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 194 matching lines @@
 {
     if (element().isDisabledOrReadOnly())
         return;
     const String& key = event->keyIdentifier();
     if (key == "Up")
         spinButtonStepUp();
     else if (key == "Down")
         spinButtonStepDown();
     else
         return;
-    element().dispatchFormControlChangeEvent();
     event->setDefaultHandled();
 }
 
 void TextFieldInputType::forwardEvent(Event* event)
 {
     if (SpinButtonElement* spinButton = spinButtonElement()) {
         spinButton->forwardEvent(event);
         if (event->defaultHandled())
             return;
     }
@@ skipping 333 matching lines @@
 bool TextFieldInputType::shouldSpinButtonRespondToMouseEvents()
 {
     return !element().isDisabledOrReadOnly();
 }
 
 bool TextFieldInputType::shouldSpinButtonRespondToWheelEvents()
 {
     return shouldSpinButtonRespondToMouseEvents() && element().focused();
 }
 
-void TextFieldInputType::spinButtonDidReleaseMouseCapture()
-{
-    element().dispatchFormControlChangeEvent();
-}
-
 } // namespace WebCore