Bug 49182 What should canceling setRawClasspath do ?
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/viewsupport/GoToBackProgressMonitorDialog.java
if (totalWork == UNKNOWN) {
				progressIndicator.beginAnimatedTask();
			} else {
				progressIndicator.beginTask(totalWork);
			}
		}
		public void done() {
			if (fWrapped != null) {
				fWrapped.done();
			}
			if (fInBackground) {
				return;
			}
			getShell().getDisplay().asyncExec(new Runnable() {
				public void run() {
					internalDone();
				}
			});
		}
		
		private void internalDone() {
			if (!progressIndicator.isDisposed()) {
				progressIndicator.sendRemainingWork();
				progressIndicator.done();
			}
		}
		public void setTaskName(final String name) {
			if (fWrapped != null) {
				fWrapped.setTaskName(name);