Popup open and hide using Alt+KeyDown

Source/core/html/HTMLSelectElement.cpp

Index: Source/core/html/HTMLSelectElement.cpp
diff --git a/Source/core/html/HTMLSelectElement.cpp b/Source/core/html/HTMLSelectElement.cpp
index b0dc747ff14ab9cee6caa8a9264b2d0c2834ad1f..4dba84477b94982d7c189067946d7a7c0bcb7736 100644
--- a/Source/core/html/HTMLSelectElement.cpp
+++ b/Source/core/html/HTMLSelectElement.cpp
@@ -1184,6 +1184,16 @@ void HTMLSelectElement::menuListDefaultEventHandler(Event* event)
         else
             handled = false;
 
+        if (keyIdentifier == "Down" && event->isKeyboardEvent() && toKeyboardEvent(event)->altKey()) {

[keishi, 2014/07/03 07:13:38]

We already open the popup on alt+down/up. It is implemented in
platformHandleKeydownEvent in HTMLSelectElementWin.cpp.
We don't want this shortcut on Mac so this is unnecessary.
We just need to close the popup on alt+down/up.

[Habib Virji, 2014/07/03 08:17:34]

@keishi: What about linux? It does not work for linux, alt+down. Should ifdef
flag be added to make it work in Linux?

[keishi, 2014/07/03 08:38:47]

I think we want this shortcut for Windows and Linux.
We can't share code if we use file names to specify behavior for each
platform(e.g. *Win.cpp and *Linux.cpp)
I think we should use RenderTheme. Please refer to
RenderTheme::shouldOpenPickerWithF4Key

[Habib Virji, 2014/07/03 17:24:04]

Done.

+            focus();
+            if (!renderer() || !renderer()->isMenuList() || isDisabledFormControl())
+                return;
+            saveLastSelection();
+            if (RenderMenuList* menuList = toRenderMenuList(renderer()))
+                menuList->showPopup();
+            event->setDefaultHandled();
+        }
+
         if (handled && static_cast<size_t>(listIndex) < listItems.size())
             selectOption(listToOptionIndex(listIndex), DeselectOtherOptions | DispatchInputAndChangeEvent | UserDriven);