Bug 180701 [JFace] API - Popup dialog is creating image descriptors every time it is opened
We are not caching the imageDescriptors from PopupDialog but are recreating them all of the time. This is likely not a serious issue but it will generate garbage. Also the images are not looked up using bundles so they cannot be overridden in other Locales. As they are currently symmetric this is not an issue but they should be looked up in the same way we do it in JFaceResources when this fixed.
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/JFaceResources.java
*            the symbolic name of the image
	 * @param path
	 *            the path of the image file relative to the base of the
	 *            workbench plug-ins install directory
	 * @param fallback
	 *            the {@link Class} where the fallback implementation of the
	 *            image is relative to
	 * @param fallbackPath
	 *            the path relative to the fallback {@link Class}
	 * 
	 */
	private static final void declareImage(Object bundle, String key,
			String path, Class fallback, String fallbackPath) {
		
		ImageDescriptor descriptor = null;
		if (bundle != null) {
			URL url = FileLocator.find((Bundle) bundle, new Path(path), null);
			if (url != null)
				descriptor = ImageDescriptor.createFromURL(url);
		}
		
		if (descriptor == null)
			descriptor = ImageDescriptor.createFromFile(fallback, fallbackPath);
		imageRegistry.put(key, descriptor);
	}
	/**
	 * Returns the resource object with the given key in JFace's resource
	 * bundle. If there isn't any value under the given key, the key is
	 * returned.
	 *