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
private IWorkbenchAction closeAction;
    private IWorkbenchAction closeAllAction;
    
    private IWorkbenchAction closeOthersAction;
    private IWorkbenchAction closeAllSavedAction;
    private IWorkbenchAction saveAction;
    private IWorkbenchAction saveAllAction;
    private IWorkbenchAction newWindowAction;
    
    private IWorkbenchAction newEditorAction;
    private IWorkbenchAction helpContentsAction;
    private IWorkbenchAction helpSearchAction;
	
    private IWorkbenchAction dynamicHelpAction;
    
    private IWorkbenchAction aboutAction;
    private IWorkbenchAction openPreferencesAction;
    private IWorkbenchAction saveAsAction;
    private IWorkbenchAction hideShowEditorAction;
    private IWorkbenchAction savePerspectiveAction;
    private IWorkbenchAction resetPerspectiveAction;
    private IWorkbenchAction editActionSetAction;
    private IWorkbenchAction closePerspAction;
    private IWorkbenchAction lockToolBarAction;
    private IWorkbenchAction closeAllPerspsAction;
    private IWorkbenchAction showViewMenuAction;
    private IWorkbenchAction showPartPaneMenuAction;
    private IWorkbenchAction nextPartAction;
    private IWorkbenchAction prevPartAction;