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/packageview/PackageExplorerPart.java
/**
	 * Create the KeyListener for doing the refresh on the viewer.
	 */
	private void initKeyListener() {
		fViewer.getControl().addKeyListener(new KeyAdapter() {
			public void keyReleased(KeyEvent event) {
				doKeyPressed(event);
			}
		});
	}
	private void doKeyPressed(KeyEvent event) {
		if (event.stateMask != 0) 
			return;		
		
		int key= event.keyCode;
		if (key == SWT.F5) {
			fRefreshAction.selectionChanged(
				(IStructuredSelection) fViewer.getSelection());
			if (fRefreshAction.isEnabled())
				fRefreshAction.run();
		} else if (key == SWT.F4) {
			OpenTypeHierarchyUtil.open(getSelection(), getSite().getWorkbenchWindow());
		} else if (key == SWT.F3) {
			fOpenCUAction.update();
			if (fOpenCUAction.isEnabled())
				fOpenCUAction.run();
		} else if (event.character == SWT.DEL){
			fDeleteAction.update();
			if (fDeleteAction.isEnabled())
				fDeleteAction.run();