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

Source/core/html/shadow/SpinButtonElement.cpp

 /*
  * Copyright (C) 2006, 2008, 2010 Apple Inc. All rights reserved.
  * 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 42 matching lines @@
 }
 
 PassRefPtr<SpinButtonElement> SpinButtonElement::create(Document& document, SpinButtonOwner& spinButtonOwner)
 {
     RefPtr<SpinButtonElement> element = adoptRef(new SpinButtonElement(document, spinButtonOwner));
     element->setShadowPseudoId(AtomicString("-webkit-inner-spin-button", AtomicString::ConstructFromLiteral));
     element->setAttribute(idAttr, ShadowElementNames::spinButton());
     return element.release();
 }
 
-void SpinButtonElement::detach(const AttachContext& context)
-{
-    releaseCapture();
-    HTMLDivElement::detach(context);
-}
-
 void SpinButtonElement::defaultEventHandler(Event* event)
 {
     if (!event->isMouseEvent()) {
         if (!event->defaultHandled())
             HTMLDivElement::defaultEventHandler(event);
         return;
     }
 
     RenderBox* box = renderBox();
     if (!box) {
@@ skipping 20 matching lines @@
                 m_spinButtonOwner->focusAndSelectSpinButtonOwner();
             if (renderer()) {
                 if (m_upDownState != Indeterminate) {
                     // A JavaScript event handler called in doStepAction() below
                     // might change the element state and we might need to
                     // cancel the repeating timer by the state change. If we
                     // started the timer after doStepAction(), we would have no
                     // chance to cancel the timer.
                     startRepeatingTimer();
                     doStepAction(m_upDownState == Up ? 1 : -1);
+                    if (m_spinButtonOwner)
+                        m_spinButtonOwner->spinButtonDidReleaseMouseCapture();

[tkent, 2014/04/07 04:31:17]

Why pinButtonDidReleaseMouseCapture is called?  We don't release mouse capture,
and we don't want to dispatch 'change' events on mousedown.

[Habib Virji, 2014/04/07 07:33:18]

Done.

                 }
             }
             event->setDefaultHandled();
         }
     } else if (mouseEvent->type() == EventTypeNames::mouseup && mouseEvent->button() == LeftButton) {
-        stopRepeatingTimer();
+        releaseCapture();
     } else if (event->type() == EventTypeNames::mousemove) {
         if (box->pixelSnappedBorderBoxRect().contains(local)) {
             if (!m_capturing) {
                 if (LocalFrame* frame = document().frame()) {
                     frame->eventHandler().setCapturingMouseEventsNode(this);
                     m_capturing = true;
                     if (Page* page = document().page())
                         page->chrome().registerPopupOpeningObserver(this);
                 }
             }
@@ skipping 66 matching lines @@
 {
     stopRepeatingTimer();
     if (m_capturing) {
         if (LocalFrame* frame = document().frame()) {
             frame->eventHandler().setCapturingMouseEventsNode(nullptr);
             m_capturing = false;
             if (Page* page = document().page())
                 page->chrome().unregisterPopupOpeningObserver(this);
         }
     }
+    if (m_spinButtonOwner)
+        m_spinButtonOwner->spinButtonDidReleaseMouseCapture();
+
 }
 
 bool SpinButtonElement::matchesReadOnlyPseudoClass() const
 {
     return shadowHost()->matchesReadOnlyPseudoClass();
 }
 
 bool SpinButtonElement::matchesReadWritePseudoClass() const
 {
     return shadowHost()->matchesReadWritePseudoClass();
@@ skipping 37 matching lines @@
         m_upDownState = Indeterminate;
     HTMLDivElement::setHovered(flag);
 }
 
 bool SpinButtonElement::shouldRespondToMouseEvents()
 {
     return !m_spinButtonOwner || m_spinButtonOwner->shouldSpinButtonRespondToMouseEvents();
 }
 
 }