Bug 206489 [Markers] Tasks column too small in the new markers view
Tasks column too small in the new markers view. We need to take into account the twistie.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/ExtendedMarkersView.java
control.setMenu(menu);
	}
	/**
	 * Remove the category from the list of expanded ones.
	 * 
	 * @param category
	 */
	public void removeExpandedCategory(MarkerCategory category) {
		categoriesToExpand.remove(category.getName());
	}
	/**
	 * Preserve the selection for re-selection after the next update.
	 * 
	 * @param selection
	 */
	public void saveSelection(ISelection selection) {
		preservedSelection.clear();
		if (selection instanceof IStructuredSelection) {
			IStructuredSelection structured = (IStructuredSelection) selection;
			Iterator iterator = structured.iterator();
			while (iterator.hasNext()) {
				MarkerItem next = (MarkerItem) iterator.next();
				if (next.isConcrete()) {
					preservedSelection.add(new MarkerSelectionEntry(next));
					categoriesToExpand.add(next.getParent());
				} else
					categoriesToExpand.add(next);
			}
		}
	}