Bug 305703 [Viewers][CommonNavigator] remembered contributions can leak when using filters
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* @param element The element being decorated.
	 * @param labelProvider ILabelProvider the labelProvider for the receiver.
	 */
	void buildLabel(ViewerLabel updateLabel, Object element,ILabelProvider labelProvider){
			updateLabel.setText(labelProvider.getText(element));
			updateLabel.setImage(labelProvider.getImage(element));
	}
	/**
	 * Get the ColorAndFontCollector for the receiver.
	 * @return ColorAndFontCollector 
	 * @since 3.1
	 */
	protected ColorAndFontCollector getColorAndFontCollector() {
		return colorAndFontCollector;
	}
	
	protected void handleDispose(DisposeEvent event) {
		super.handleDispose(event);
		sorter = null;
		comparer = null;
		if (filters != null)
			filters.clear();
		elementMap = newHashtable(1);
		openListeners.clear();
		doubleClickListeners.clear();
		colorAndFontCollector.clear();
		postSelectionChangedListeners.clear();
	}
}