Bug 48452 Widget is disposed while closing cool bar
This is the problem that is occurring in the nightly builds. There is something happening where a cool bar is attempting to layout disposed cool bar items.
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ToolBarContributionItem.java
/**
	 * Returns the current height of the corresponding cool item.
	 * 
	 * @return the current height
	 */
	public int getCurrentHeight() {
		return currentHeight;
	}
	
	/**
	 * Sets the current height of the cool item. 
	 * Update(SIZE) should be called to adjust the widget.
	 * 
	 * @param currentHeight the current height to set
	 */
	public void setCurrentHeight(int currentHeight) {
		this.currentHeight = currentHeight;
	}
	
	/**
	 * Sets the current width of the cool item. 
	 * Update(SIZE) should be called to adjust the widget.
	 * 
	 * @param currentWidth the current width to set
	 */
	public void setCurrentWidth(int currentWidth) {
		this.currentWidth = currentWidth;
	}
}