chromium/ash/webui/common/resources/cellular_setup/cellular_setup.html

<iron-pages
    attr-for-selected="id"
    selected="[[currentPageName]]"
    selected-item="{{currentPage_}}">
  <template is="dom-if"
      if="[[shouldShowPsimFlow_(currentPageName)]]" restamp>
    <psim-flow-ui
        button-state="{{buttonState_}}"
        name-of-carrier-pending-setup="{{flowPsimBanner}}"
        delegate="[[delegate]]"
        id="psim-flow-ui"
        forward-button-label="{{forwardButtonLabel_}}">
    </psim-flow-ui>
  </template>
  <template is="dom-if"
      if="[[shouldShowEsimFlow_(currentPageName)]]" restamp>
    <esim-flow-ui
        button-state="{{buttonState_}}"
        delegate="[[delegate]]"
        id="esim-flow-ui"
        header="{{flowHeader}}"
        forward-button-label="{{forwardButtonLabel_}}">
    </esim-flow-ui>
  </template>
</iron-pages>
<button-bar
    id="buttonBar"
    button-state="[[buttonState_]]"
    forward-button-label="[[forwardButtonLabel_]]">
</button-bar>