Bug 89971 [Viewers] Viewers that use IViewerLabelProvider do too many instanceof checks
M6 Checking our viewer the calls to buildLabel are doing too many instanceof checks. As a result certain viewers (such as the table viewer) are twice as slow as they were in 3.0 due to these checks. I have written some performance suites to test the Table, Tree, List and Combo viewers. Table and Tree have this issue.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
*/
	private ListenerList postSelectionChangedListeners = new ListenerList(1);
	/**
	 * The colorAndFontCollector is an object used by viewers that
	 * support the IColorProvider, the IFontProvider and/or the 
	 * IViewerLabelProvider for color and font updates.
	 * Initialize it to have no color or font providing
	 * initially.
	 */
	protected ColorAndFontCollector colorAndFontCollector = new ColorAndFontCollector();
	/**
	 * The ColorAndFontCollector is a helper class for viewers
	 * that have color and font support ad optionally decorators.
	 * @see IColorDecorator
	 * @see IFontDecorator
	 * @see IColorProvider
	 * @see IFontProvider
	 * @see IDecoration
	 */
	protected class ColorAndFontCollector {
		Color foreground = null;
		Color background = null;
		Font font = null;
		boolean usedDecorators = false;
		IColorProvider colorProvider;
		IFontProvider fontProvider;
		/**
		 * Create a new instance of the receiver using the supplied
		 * label provider. If it is an IColorProvider or IFontProvider
		 * set these values up.