Bug 119494 [Workbench] dangerous uses of "new GC(Display)"
bundles/org.eclipse.jface/src/org/eclipse/jface/action/ActionContributionItem.java
protected boolean isEnabledAllowed() {
        if (getParent() == null)
            return true;
        Boolean value = getParent().getOverrides().getEnabled(this);
        return (value == null) ? true : value.booleanValue();
    }
    /**
     * The <code>ActionContributionItem</code> implementation of this 
     * <code>ContributionItem</code> method extends the super implementation
     * by also checking whether the command corresponding to this action is active.
     */
    public boolean isVisible() {
        return super.isVisible() && isCommandActive();
    }
    /**
     * Sets the presentation mode, which is the bitwise-or of the 
     * <code>MODE_*</code> constants.
     * 
     * @param mode the presentation mode settings
     * 
     * @since 3.0
     */
    public void setMode(int mode) {
        this.mode = mode;
        update();
    }
    /**
     * The action item implementation of this <code>IContributionItem</code>
     * method calls <code>update(null)</code>.
     */