Bug 139986 [CommonNavigator] Convert catch(Error/Throwable) to SafeRunner
In several places the CN framework uses catch(Error/Throwable) to ensure that code does not bring the framework down. Change these to use SafeRunner.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/NavigatorContentExtension.java
.getExtension(overridingDescriptor));
			}
		}
		if (overridingExtensions.size() == 0) {
			return NO_EXTENSIONS;
		}
		if (Policy.DEBUG_EXTENSION_SETUP) {
			System.out.println(this +  " overriding: "+
					"(trigger pt: " + anElement + "): " + overridingExtensions); 
		}
		return (NavigatorContentExtension[]) overridingExtensions
				.toArray(new NavigatorContentExtension[overridingExtensions
						.size()]);
	}
	/**
	 * 
	 * @param anElement
	 *            The element for the query.
	 * @return Returns the overridingExtensions.
	 */
	public NavigatorContentExtension[] getOverridingExtensionsForPossibleChild(
			Object anElement) {
		if (!descriptor.hasOverridingExtensions()) {
			return NO_EXTENSIONS;
		}
		NavigatorContentDescriptor overridingDescriptor;
		Set overridingExtensions = new LinkedHashSet();
		for (Iterator contentDescriptorsItr = descriptor
				.getOverriddingExtensions().iterator(); contentDescriptorsItr
				.hasNext();) {