Bug 198971 [CommonNavigator] Provide extension schema for setting help ID
I haven't been able to find a way to set the help ID for a view using the common resource navigator. It seems that having schema support for this would be the best way to handle this.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/extensions/NavigatorViewerDescriptor.java
/*
	 * (non-Javadoc)
	 * 
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		return "ViewerDescriptor[" + viewerId + "]"; 
	}
	/**
	 * Update the popupMenuId. If a value is already set, then a warning message
	 * will be logged.
	 * 
	 * @param newPopupMenuId
	 *            The new popup menu id.
	 */
	 void setPopupMenuId(String newPopupMenuId) {
		if (newPopupMenuId != null) {
			if (popupMenuId != null) {
				NavigatorPlugin
						.log(
								IStatus.WARNING,
								0,
								NLS
										.bind(
												CommonNavigatorMessages.NavigatorViewerDescriptor_Popup_Menu_Overridden,
												new Object[] { getViewerId(),
														popupMenuId,
														newPopupMenuId }), null);
			}
			popupMenuId = newPopupMenuId;