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
input= getSite().getPage().getInput();
			if (!(input instanceof IJavaElement) && input instanceof IAdaptable)
				input= ((IAdaptable)input).getAdapter(IJavaElement.class);
			
			else
				return;
		}
		if (findElementToSelect((IJavaElement)input) != null)
			adjustInputAndSetSelection((IJavaElement)input);
	}
	final protected void setHelp() {
		JavaUIHelp.setHelp(fViewer, getHelpContextId());
	}
	/**
	 * Returns the context ID for the Help system
	 * 
	 * @return	the string used as ID for the Help context
	 */
	abstract protected String getHelpContextId();
	/**
	 * Adds additional listeners to this view.
	 */
	protected void hookViewerListeners() {
		fViewer.addSelectionChangedListener(new ISelectionChangedListener() {
			public void selectionChanged(SelectionChangedEvent event) {
				if (!fProcessSelectionEvents)
					return;
				if (JavaBrowsingPreferencePage.openEditorOnSingleClick())
					new ShowInEditorAction().run(event.getSelection(), getSite().getPage());