Do not dispatch 'change' events during pressing spin buttons for input[type=number].

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;
+    if (element().focused())

[tkent, 2014/03/18 08:26:20]

Why is the focus check needed? It looks unnecessary.

+        element().dispatchFormControlChangeEvent();
     event->setDefaultHandled();
 }
 
 void TextFieldInputType::forwardEvent(Event* event)
 {
     if (SpinButtonElement* spinButton = spinButtonElement()) {
         spinButton->forwardEvent(event);
         if (event->defaultHandled())
             return;
     }
@@ skipping 326 matching lines @@
 bool TextFieldInputType::shouldSpinButtonRespondToMouseEvents()
 {
     return !element().isDisabledOrReadOnly();
 }
 
 bool TextFieldInputType::shouldSpinButtonRespondToWheelEvents()
 {
     return shouldSpinButtonRespondToMouseEvents() && element().focused();
 }
 
+void TextFieldInputType::spinButtonDidReleaseMouseCapture()
+{
+    // Sending dispatch change event only when in focus,
+    // as when out of focus change event is triggered from setValue::DispatchChangeEvent.
+    if (element().focused())

[tkent, 2014/03/18 08:26:20]

Ditto.

+        element().dispatchFormControlChangeEvent();
+}
+
 } // namespace WebCore