Bug 202316 [Forms] Add gradient sharing support for FormHeading
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/internal/forms/widgets/FormHeading.java
public MessageRegion() {
		}
		public boolean isDisposed() {
			Control c = getMessageControl();
			return c != null && c.isDisposed();
		}
		public boolean isEmpty() {
			Control c = getMessageControl();
			if (c == null)
				return true;
			return !c.getVisible();
		}
		public int getFontHeight() {
			if (fontHeight == -1) {
				Control c = getMessageControl();
				if (c == null)
					return 0;
				GC gc = new GC(c.getDisplay());
				gc.setFont(c.getFont());
				fontHeight = gc.getFontMetrics().getHeight();
				gc.dispose();
			}
			return fontHeight;
		}
		public int getFontBaselineHeight() {
			if (fontBaselineHeight == -1) {
				Control c = getMessageControl();
				if (c == null)
					return 0;
				GC gc = new GC(c.getDisplay());