Bug 156747 Adopt Resource.getDevice() in the JFace resource managers
SWT has recently added a Resource.getDevice() method. This allows several improvements to be made to the JFace resource managers: 1. The (inefficient and complex) heuristics that detect a device by creating temporary resources can be removed. 2. The one-argument descriptor factories that don't take a Device can be made just as efficient as the two-argument versions. 3. The descriptor factory methods that take a Device can be deprecated, since the second argument is no longer required and the one-argument version is just as efficient.
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/FontDescriptor.java
/**
     * Creates a FontDescriptor that describes an existing font. The resulting
     * descriptor depends on the Font. Disposing the Font while the descriptor
     * is still in use may throw a graphic disposed exception.
     * 
     * @since 3.1
     *
     * @param font a font to describe
     * @param originalDevice must be the same Device that was passed into
     * the font's constructor when it was first created.
     * @return a newly created FontDescriptor.
     */
    public static FontDescriptor createFrom(Font font, Device originalDevice) {
        return new ArrayFontDescriptor(font, originalDevice);
    }