Bug 163360 [Field Assist] - API - Provide ControlDecoration constructor without specifying decoration
Currently you can only create a ControlDecoration by specifying the control and the decoration in the constructor. This works nicely when the decoration is static (ie, always content assist). But there are use cases where the decoration changes depending on the state of the field, and at creation time, it's not clear which decoration will be set. Having a constructor that doesn't require a decoration would be nice.
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ControlDecoration.java
}
	}
	/**
	 * Hide the control decoration. This message has no effect if the decoration
	 * is already hidden.
	 */
	public void hide() {
		if (visible) {
			visible = false;
			update();
		}
	}
	/**
	 * Set the decoration for this control decoration to the specified
	 * decoration. Update any visuals appropriate for the new decoration.
	 * 
	 * @param decoration
	 *            the decoration to be shown adjacent to the control
	 */
	public void setDecoration(FieldDecoration decoration) {
		this.decoration = decoration;
		update();
	}
	/**
	 * Get the boolean that controls whether the decoration is shown only when
	 * the control has focus. The default value of this setting is
	 * <code>false</code>.
	 * 
	 * @return <code>true</code> if the decoration should only be shown when
	 *         the control has focus, and <code>false</code> if it should