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

Source/core/html/forms/TextFieldInputType.cpp

Index: Source/core/html/forms/TextFieldInputType.cpp
diff --git a/Source/core/html/forms/TextFieldInputType.cpp b/Source/core/html/forms/TextFieldInputType.cpp
index 041d0307d823880aa98a8326103e359f9742e37a..aa60f4e3a43e589fb7042f7a434e51e6aafeafa7 100644
--- a/Source/core/html/forms/TextFieldInputType.cpp
+++ b/Source/core/html/forms/TextFieldInputType.cpp
@@ -186,7 +186,7 @@ void TextFieldInputType::setValue(const String& sanitizedValue, bool valueChange
         break;
     }
 
-    if (!input->focused())
+    if (!input->focused() && eventBehavior != DispatchNoEvent)

[tkent, 2014/04/04 01:31:46]

I think this change will make an incompatible behavior change.
e.g.

input.focus();
... a user types into the input.
input.value = "abc"
input.blur();

This should NOT dispatch a change event on blur in the current policy.

[Habib Virji, 2014/04/04 09:24:05]

Done.

         input->setTextAsOfLastFormControlChangeEvent(sanitizedValue);
 }
 
@@ -212,6 +212,7 @@ void TextFieldInputType::handleKeydownEventForSpinButton(KeyboardEvent* event)
         spinButtonStepDown();
     else
         return;
+    element().dispatchFormControlChangeEvent();
     event->setDefaultHandled();
 }
 
@@ -558,4 +559,9 @@ bool TextFieldInputType::shouldSpinButtonRespondToWheelEvents()
     return shouldSpinButtonRespondToMouseEvents() && element().focused();
 }
 
+void TextFieldInputType::spinButtonDidReleaseMouseCapture()
+{
+    element().dispatchFormControlChangeEvent();
+}
+
 } // namespace WebCore