Selectmenu: webkit based browsers require 2 clicks to open

Clicking for the first time after page load the selectmenu button on the text node triggers a focus, rather than opening the select.

To reproduce:

• use a webkit browser (tried with chrome (26/canary), safari 5.1.7, chrome for android (stable))
• open the selectmenu demo from the wiki
• click on any text contained within the button, e.g. the "d" in "Medium"
• the button will get focused, but the select won't open. Any further click will open the select correctly

I have also tried using GIT HEAD, and the bug is still reproducible.