Bug 129246 [JFace] - API - access to images and colors for standard field decorations
bundles/org.eclipse.jface/src/org/eclipse/jface/fieldassist/FieldDecorationRegistry.java
public static FieldDecorationRegistry getDefault() {
		if (defaultInstance == null) {
			defaultInstance = new FieldDecorationRegistry();
		}
		return defaultInstance;
	}
	/**
	 * Set the default FieldDecorationRegistry.
	 * 
	 * @param defaultRegistry
	 *            the singleton FieldDecorationRegistry that is used to manage
	 *            shared field decorations.
	 */
	public static void setDefault(FieldDecorationRegistry defaultRegistry) {
		defaultInstance = defaultRegistry;
	}
	/**
	 * Construct a FieldDecorationRegistry.
	 * 
	 * @param decorationWidth
	 *            the width in pixels reserved for decorations
	 * @param decorationHeight
	 *            the height in pixels reserved for decorations
	 */
	public FieldDecorationRegistry() {
		maxDecorationWidth = 0;
		maxDecorationHeight = 0;
	}
	/**
	 * Get the maximum width (in pixels) of any decoration retrieved so far in