Bug 194209 [CommonNavigator] ProblemsLabelDecorator does not scale well with Project Explorer
When opening a project, The ProblemsLabelDecorator fires a LabelProviderChangedEvent for all resources contained in this project. While in a ProblemTreeViewer, like the Package Explorer, this is handled in an optimized way by filtering out updates to resources which are not realized in the tree view, the Common Navigator has no such means. The result is that for a project with e.g. 50000 resources, a label update for 50000 elements is triggered even though the project is not even expanded in the view.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonNavigator.java
* method.
	 * </p>
	 * 
	 * @see org.eclipse.ui.part.ViewPart#saveState(org.eclipse.ui.IMemento)
	 */
	public void saveState(IMemento aMemento) {
		aMemento.putInteger(LINKING_ENABLED, (isLinkingEnabled) ? 1 : 0);
		super.saveState(aMemento);
		commonManager.saveState(aMemento);
		commonViewer.getNavigatorContentService().saveState(aMemento);
	}
	/**
	 * <p>
	 * Force the workbench to focus on the Common Navigator tree.
	 * </p>
	 * 
	 * @see org.eclipse.ui.part.WorkbenchPart#setFocus()
	 */
	public void setFocus() {
		if (commonViewer != null) {
			commonViewer.getTree().setFocus();
		}
	}
	/**
	 * <p>
	 * Set the selection to the Common Navigator tree, and expand nodes if
	 * necessary. Use caution when invoking this method as it can cause
	 * Navigator Content Extensions to load, thus causing plugin activation.
	 * </p>
	 *