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 168 matching lines @@
     case DispatchInputAndChangeEvent: {
         input->dispatchFormControlInputEvent();
         input->dispatchFormControlChangeEvent();
         break;
     }
 
     case DispatchNoEvent:
         break;
     }
 
-    if (!input->focused())
+    if (!input->focused() && eventBehavior != DispatchNoEvent)

[tkent, 2014/04/04 01:31:46]

I think this change will make an incompatible behavior change.
e.g.

input.focus();
... a user types into the input.
input.value = "abc"
input.blur();

This should NOT dispatch a change event on blur in the current policy.

[Habib Virji, 2014/04/04 09:24:05]

Done.

         input->setTextAsOfLastFormControlChangeEvent(sanitizedValue);
 }
 
 void TextFieldInputType::handleKeydownEvent(KeyboardEvent* event)
 {
     if (!element().focused())
         return;
     if (Chrome* chrome = this->chrome()) {
         chrome->client().handleKeyboardEventOnTextField(element(), *event);
         return;
     }
     event->setDefaultHandled();
 }
 
 void TextFieldInputType::handleKeydownEventForSpinButton(KeyboardEvent* event)
 {
     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 326 matching lines @@
 bool TextFieldInputType::shouldSpinButtonRespondToMouseEvents()
 {
     return !element().isDisabledOrReadOnly();
 }
 
 bool TextFieldInputType::shouldSpinButtonRespondToWheelEvents()
 {
     return shouldSpinButtonRespondToMouseEvents() && element().focused();
 }
 
+void TextFieldInputType::spinButtonDidReleaseMouseCapture()
+{
+    element().dispatchFormControlChangeEvent();
+}
+
 } // namespace WebCore