Bug 243758 [Contributions] Accelerators in menus are not installed until menu shown
bundles/org.eclipse.jface/src/org/eclipse/jface/window/ApplicationWindow.java
static final int VGAP = 2;
        static final int BAR_SIZE = 23;
        protected Point computeSize(Composite composite, int wHint, int hHint,
                boolean flushCache) {
            if (wHint != SWT.DEFAULT && hHint != SWT.DEFAULT) {
				return new Point(wHint, hHint);
			}
            Point result = new Point(0, 0);
            Control[] ws = composite.getChildren();
            for (int i = 0; i < ws.length; i++) {
                Control w = ws[i];
                boolean hide = false;
                if (getToolBarControl() == w) {
                    if (!toolBarChildrenExist()) {
                        hide = true;
                        result.y += BAR_SIZE; 
                    }
                } else if (getCoolBarControl() == w) {
                    if (!coolBarChildrenExist()) {
                        hide = true;
                        result.y += BAR_SIZE;
                    }
                } else if (statusLineManager != null
                        && statusLineManager.getControl() == w) {
                } else if (i > 0) {