Replacing old reference to $wnd.__captureElem with @com.google.gwt.user.client.impl.DOMImplStandard::captureElem.

Patch by: jlabanca
Review by: jgw



git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7355 8db76d5a-ed1c-0410-87a9-c151d255dfc7