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
* required.
		 * @param control
		 */
		public void applyFontsAndColors(TreeItem control) {
			
			if(colorProvider == null){
				if(usedDecorators){
					
					if(background != null)
						control.setBackground(background);
				
					if(foreground != null)
						control.setForeground(foreground);
				}
			}
			else{
				
				control.setBackground(background);
				control.setForeground(foreground);
			}
			
			if(fontProvider == null){
				if(usedDecorators && font != null)
					control.setFont(font);
			}
			else
				control.setFont(font);
			
			clear();
		}