Revert "Remove gwt.logging.popupHandler"

This reverts commit f15d4aaa6bee4715c3dce221775c039efdd0c28f.
Released GWT still needs this property.
Google will have to filter it out in the build process.

Change-Id: Ie487bd32d741c42bd5f79d2c80ebe8976e667200
1 file changed