CR 6633275 is a technical side of the new client Java feature: shaped & translucent windows. In 6u10 this feature was accessible via com.sun.awt.AWTUtilities class, however in JDK7 we need some public java.awt API for it.
JDK-6837004java.awt.GraphicsDevice.setFullScreenWindow throws NPE for windows with background color not set
JDK-4479178RFE: Support for Transparent windows required
JDK-6877122Many javadoc warnings from java.awt.Window, other awt classes
JDK-6812298Dynamic GraphicsConfig changes don't work on X11 platforms