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

Source/core/html/shadow/SpinButtonElement.cpp

Index: Source/core/html/shadow/SpinButtonElement.cpp
diff --git a/Source/core/html/shadow/SpinButtonElement.cpp b/Source/core/html/shadow/SpinButtonElement.cpp
index a9ec4faf8b4a46cabfa32efdca6a572fdb32856c..34cdcbe481b4de4e241195dfd3c97696819dc4c6 100644
--- a/Source/core/html/shadow/SpinButtonElement.cpp
+++ b/Source/core/html/shadow/SpinButtonElement.cpp
@@ -112,7 +112,7 @@ void SpinButtonElement::defaultEventHandler(Event* event)
             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) {
@@ -199,6 +199,9 @@ void SpinButtonElement::releaseCapture()
                 page->chrome().unregisterPopupOpeningObserver(this);
         }
     }
+    if (m_spinButtonOwner)
+        m_spinButtonOwner->spinButtonDidReleaseMouseCapture();
+
 }
 
 bool SpinButtonElement::matchesReadOnlyPseudoClass() const