The client code has a "com.sun.awt.AWTUtilities" class which at some point(jdk6u10) in the past was used as a kind of "public" API.
In jdk9 this class is inaccessible and all its functionality was already provided by the public API, so this class can be removed.
AWTUtilities.isTranslucencySupported()/AWTUtilities.isWindowShapingSupported()
-> GraphicsDevice.isWindowTranslucencySupported()
AWTUtilities.setWindowOpacity()/AWTUtilities.getWindowOpacity()
-> Window.setOpacity/getOpacity
AWTUtilities.getWindowShape()/AWTUtilities.setWindowShape()
-> Window.setShape()/getShape()
AWTUtilities.setWindowOpaque/AWTUtilities.isWindowOpaque
-> setBackground()/isOpaque()
AWTUtilities.isTranslucencyCapable
-> GraphicsConfiguration.isTranslucencyCapable()
AWTUtilities.setComponentMixingCutoutShape
-> Component.setMixingCutoutShape()
CSR will be created after technical review.