Bug 11748 switch to new DecoratorManager API
From the workbench change notes: API changes IWorkbenchPartSite.getDecoratorManager() - As the DecoratorManager has proven to be required for more than just IWorkbenchPartSites we have moved getDecoratorManager() to IWorkbench and deprecated the getDecoratorManager() in IWorkbenchPartSite. The one in IWorkbenchPartSite will be removed after the other Eclipse components have had a chance to switch to the new API.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/browsing/JavaBrowsingPart.java
* Adds filters the viewer of this part.
	 */
	protected void addFilters() {
		
	}
	/**
	 * Creates the the content provider of this part.
	 */
	protected BaseJavaElementContentProvider createContentProvider() {
		return new JavaElementContentProvider(true, this); 
	}
	protected void setInitialInput() {
		
		ISelection selection= getSite().getPage().getSelection();
		Object input= getElementFromSingleSelection(selection);
		if (!(input instanceof IJavaElement)) {
			
			input= getSite().getPage().getInput();
			if (!(input instanceof IJavaElement) && input instanceof IAdaptable)
				input= ((IAdaptable)input).getAdapter(IJavaElement.class);
		}
		setInput(findInputForJavaElement((JavaElement)input));		
	}
	protected void setInitialSelection() {
		
		Object input;
		ISelection selection= getSite().getPage().getSelection();
		if (selection != null && !selection.isEmpty())
			input= getElementFromSingleSelection(selection);
		else {