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

Source/core/html/forms/InputType.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2007 Samuel Weinig (sam@webkit.org)
  * Copyright (C) 2009, 2010, 2011, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2012 Samsung Electronics. All rights reserved.
  *
@@ skipping 916 matching lines @@
     if (!current.isFinite()) {
         current = defaultValueForStepUp();
         const Decimal nextDiff = step * n;
         if (current < stepRange.minimum() - nextDiff)
             current = stepRange.minimum() - nextDiff;
         if (current > stepRange.maximum() - nextDiff)
             current = stepRange.maximum() - nextDiff;
         setValueAsDecimal(current, DispatchNoEvent, IGNORE_EXCEPTION);
     }
     if ((sign > 0 && current < stepRange.minimum()) || (sign < 0 && current > stepRange.maximum())) {
-        setValueAsDecimal(sign > 0 ? stepRange.minimum() : stepRange.maximum(), DispatchInputAndChangeEvent, IGNORE_EXCEPTION);
+        setValueAsDecimal(sign > 0 ? stepRange.minimum() : stepRange.maximum(), DispatchChangeEvent, IGNORE_EXCEPTION);
         return;
     }
-    applyStep(current, n, AnyIsDefaultStep, DispatchInputAndChangeEvent, IGNORE_EXCEPTION);
+    applyStep(current, n, AnyIsDefaultStep, DispatchChangeEvent, IGNORE_EXCEPTION);
 }
 
 void InputType::countUsageIfVisible(UseCounter::Feature feature) const
 {
     if (RenderStyle* style = element().renderStyle()) {
         if (style->visibility() != HIDDEN)
             UseCounter::count(element().document(), feature);
     }
 }
 
 Decimal InputType::findStepBase(const Decimal& defaultValue) const
 {
     Decimal stepBase = parseToNumber(element().fastGetAttribute(minAttr), Decimal::nan());
     if (!stepBase.isFinite())
         stepBase = parseToNumber(element().fastGetAttribute(valueAttr), defaultValue);
     return stepBase;
 }
 
 StepRange InputType::createStepRange(AnyStepHandling anyStepHandling, const Decimal& stepBaseDefault, const Decimal& minimumDefault, const Decimal& maximumDefault, const StepRange::StepDescription& stepDescription) const
 {
     const Decimal stepBase = findStepBase(stepBaseDefault);
     const Decimal minimum = parseToNumber(element().fastGetAttribute(minAttr), minimumDefault);
     const Decimal maximum = parseToNumber(element().fastGetAttribute(maxAttr), maximumDefault);
     const Decimal step = StepRange::parseStep(anyStepHandling, stepDescription, element().fastGetAttribute(stepAttr));
     return StepRange(stepBase, minimum, maximum, step, stepDescription);
 }
 
 } // namespace WebCore