Bug 157985 [Workbench] Add 'Hide toolbar' action to context menu
M2 The 'Hide toolbar' action should be added to the context menu on toolbars. That's where I first looked for it.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/WorkbenchActionBuilder.java
if (workbenchPage != null) {					
         IWorkbenchPageCommandSupport workbenchPageCommandSupport = (IWorkbenchPageCommandSupport) workbenchPage.getCommandSupport();
         workbenchPageCommandSupport.getCompoundCommandHandlerService().addCommandHandlerService(commandHandlerServiceB);
         }
         }
         }
         });
         menu.add(new Action("Remove handler B from the workbench page") {
         public void run() {
         IWorkbench workbench = PlatformUI.getWorkbench();
         IWorkbenchWindow workbenchWindow = workbench.getActiveWorkbenchWindow();
         if (workbenchWindow != null) {
         IWorkbenchPage workbenchPage = workbenchWindow.getActivePage();
         
         if (workbenchPage != null) {					
         IWorkbenchPageCommandSupport workbenchPageCommandSupport = (IWorkbenchPageCommandSupport) workbenchPage.getCommandSupport();
         workbenchPageCommandSupport.getCompoundCommandHandlerService().removeCommandHandlerService(commandHandlerServiceB);
         }
         }
         }
         });
         */
        return menu;
    }
    /**
	 * Adds a <code>GroupMarker</code> or <code>Separator</code> to a menu.
	 * The test for whether a separator should be added is done by checking for
	 * the existence of a preference matching the string
	 * useSeparator.MENUID.GROUPID that is set to <code>true</code>.