Bug 125600 [Field Assist] - popup shell should be resizable with size retained
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/ContentProposalAdapter.java
/*
	 * The lightweight popup used to show content proposals for a text field. If
	 * additional information exists for a proposal, then selecting that
	 * proposal will result in the information being displayed in a secondary
	 * popup.
	 */
	class ContentProposalPopup extends PopupDialog {
		/*
		 * The listener we install on the popup and related controls to
		 * determine when to close the popup. Some events (move, resize, close,
		 * deactivate) trigger closure as soon as they are received, simply
		 * because one of the registered listeners received them. Other events
		 * depend on additional circumstances.
		 */
		private final class PopupCloserListener implements Listener {