After switching the menu button visibility from INVISIBLE to GONE in https://github.com/brave/brave-core/pull/35051, the shred button became the rightmost child of menu_button_container and lost the spacing the menu button used to contribute via its paddingEnd. Apply an end margin equal to the toolbar's start inset when the menu button is hidden so the icon stays clear of the screen edge and the toolbar reads symmetrically. Resolves: https://github.com/brave/brave-browser/issues/55012