Bug 139483 IDEIdleHelper should be a system job
RC2 The IDEIdleHelper is not a system job so you periodically get a "Collecting garbage" job showing up in the ProgressView.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/IDEIdleHelper.java
* The multiple of the last gc duration before we will consider doing
	 * another one.
	 */
	private static final int GC_DELAY_MULTIPLIER = 60;
	/**
	 * The time interval of no keyboard or mouse events after which the system 
	 * is considered idle.
	 */
	private static final int IDLE_INTERVAL = 5000;
	/**
	 * The name of the boolean system property that specifies whether explicit
	 * garbage collection is enabled.
	 */
	private static final String PROP_GC = "ide.gc"; 
	/**
	 * The name of the integer system property that specifies the minimum time 
	 * interval in milliseconds between garbage collections.
	 */
	private static final String PROP_GC_INTERVAL = "ide.gc.interval"; 
	/**
	 * The name of the integer system property that specifies the maximum 
	 * duration for a garbage collection. If this duration is ever exceeded, the 
	 * explicit gc mechanism is disabled for the remainder of the session.
	 */
	private static final String PROP_GC_MAX = "ide.gc.max"; 
	protected IWorkbenchConfigurer configurer;
	private Listener idleListener;
	/**
	 * The last time we garbage collected.
	 */