Bug 299209 [CommonNavigator] Clean up error reporting for pipelined extensions
A catch block was missing for one of them, and the error report does not provide the extension Id that had the problem.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorPipelineService.java
}
	private void pipelineInterceptAdd(PipelinedShapeModification anAddModification, ContributorTrackingSet trackedSet, INavigatorContentDescriptor descriptor) {
		if(descriptor.hasOverridingExtensions()) {
			Set overridingDescriptors = descriptor.getOverriddingExtensions();
			for (Iterator overridingDescriptorsItr = overridingDescriptors.iterator(); overridingDescriptorsItr
					.hasNext();) {
				INavigatorContentDescriptor overridingDescriptor = (INavigatorContentDescriptor) overridingDescriptorsItr.next();
				if(contentService.isVisible(overridingDescriptor.getId()) && contentService.isActive(overridingDescriptor.getId())) {
					trackedSet.setContributor((NavigatorContentDescriptor) overridingDescriptor);
					NavigatorContentExtension extension = contentService.getExtension(overridingDescriptor);
					((IPipelinedTreeContentProvider) extension.internalGetContentProvider()).interceptAdd(anAddModification);
					trackedSet.setContributor(null);
					pipelineInterceptAdd(anAddModification, trackedSet, overridingDescriptor);
				}
			}
		}
	}
	/**
	 * Intercept attempts to remove elements directly from the viewer.
	 * 
	 * <p>
	 * For content extensions that reshape the structure of children in a
	 * viewer, their overridden extensions may sometimes use optimized refreshes
	 * to remove elements to the tree. These attempts must be intercepted and
	 * mapped to the correct set of model elements in the overriding extension.
	 * Clients may add, remove, or modify elements in the given set of removed
	 * children. Clients should return a set for downstream extensions to
	 * massage further.
	 * </p>
	 * <p>