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

Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp

 /*
  * Copyright (C) 2010 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:
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@@ skipping 222 matching lines @@
     if (DateTimeEditElement* edit = dateTimeEditElement())
         edit->stepDown();
 }
 
 void BaseMultipleFieldsDateAndTimeInputType::spinButtonStepUp()
 {
     if (DateTimeEditElement* edit = dateTimeEditElement())
         edit->stepUp();
 }
 
+void BaseMultipleFieldsDateAndTimeInputType::spinButtonDidReleaseMouseCapture()
+{
+    if (element().focused())

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

Why is this check needed?

We should dispatch two change events in the following scenario:
 - Mousedown on a spin button
   INPUT gets focus
 - The INPUT looses focus for some reasons.
   The first 'change' event should be dispatched.
 - Mouseup on a spin button
  The second 'change' event should be dispatch if the value is changed.

[Habib Virji, 2014/03/18 17:37:27]

It is needed since releaseCapture is called from detach, resulting in change
event dispatch.   This is to just make sure dispatch event only when in focus. 

Added condition in SpinButton to dispatch a change event in case of mouseDown
and also if mouseout occurs after being in focus. 

On 2014/03/18 08:26:20, tkent wrote:

[tkent, 2014/03/31 07:50:39]

I see.  We should not dispatch any events in detach().
However, if the value of an INPUT element was changed, we have to dispatch a
'change' event.  Hmm we should change the behavior so that we release mouse
capturing when the host INPUT element looses focus.

+        element().dispatchFormControlChangeEvent();
+}
+
 bool BaseMultipleFieldsDateAndTimeInputType::isPickerIndicatorOwnerDisabledOrReadOnly() const
 {
     return element().isDisabledOrReadOnly();
 }
 
 void BaseMultipleFieldsDateAndTimeInputType::pickerIndicatorChooseValue(const String& value)
 {
     if (element().isValidValue(value)) {
         element().setValue(value, DispatchInputAndChangeEvent);
         return;
@@ skipping 344 matching lines @@
         clearButton->setInlineStyleProperty(CSSPropertyPointerEvents, CSSValueNone);
     } else {
         clearButton->removeInlineStyleProperty(CSSPropertyOpacity);
         clearButton->removeInlineStyleProperty(CSSPropertyPointerEvents);
     }
 }
 
 } // namespace WebCore
 
 #endif