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

Source/core/html/HTMLTextFormControlElement.cpp

Index: Source/core/html/HTMLTextFormControlElement.cpp
diff --git a/Source/core/html/HTMLTextFormControlElement.cpp b/Source/core/html/HTMLTextFormControlElement.cpp
index 916142fb8104317dde9c0ad81fbbf9b799dc550a..8155d8abbda18e8f195c21f2a3bc030a982261b7 100644
--- a/Source/core/html/HTMLTextFormControlElement.cpp
+++ b/Source/core/html/HTMLTextFormControlElement.cpp
@@ -185,8 +185,8 @@ void HTMLTextFormControlElement::select()
 void HTMLTextFormControlElement::dispatchFormControlChangeEvent()
 {
     if (m_textAsOfLastFormControlChangeEvent != value()) {
-        dispatchChangeEvent();
         setTextAsOfLastFormControlChangeEvent(value());
+        dispatchChangeEvent();
     }
     setChangedSinceLastFormControlChangeEvent(false);
 }