chrome/browser/resources/side_panel/user_notes/app.html

<style include="cr-hidden-style">
  :host {
    align-items: center;
    display: flex;
    flex-direction: column;
  }

  sp-empty-state {
    width: 229px;
  }

  user-note-overviews-list,
  user-notes-list {
    align-self: stretch;
    flex: 1;
  }
</style>

<template is="dom-if"
    if="[[shouldShowEmptyOrGuestState(state_, viewingOverviews_)]]"
    restamp>
  <sp-empty-state
      guest$="[[isGuestMode_()]]"
      image-path="./images/user_notes_empty.svg"
      dark-image-path="./images/user_notes_empty_dark.svg"
      heading="[[getEmptyTitle_()]]"
      body="[[getEmptyBody_()]]">
  </sp-empty-state>
</template>
<template is="dom-if"
    if="[[shouldShowAddButton_(state_, notes_)]]">
  <cr-button
      aria-label="$i18n{addANote}"
      class="floating-button"
      hidden="[[isGuestMode_()]]"
      on-click="onAddNoteButtonClick_">
    <iron-icon slot="prefix-icon" icon="cr:add"></iron-icon>
    $i18n{addANote}
  </cr-button>
</template>
<template is="dom-if"
    if="[[shouldShowOverviews_(state_)]]"
    restamp>
  <user-note-overviews-list overviews="[[overviews_]]"
      on-current-tab-overview-selected="onCurrentTabOverviewSelected_"
      on-start-note-creation="onStartNoteCreation_">
  </user-note-overviews-list>
</template>
<template is="dom-if"
    if="[[shouldShowPageNotes_(state_)]]"
    restamp>
  <user-notes-list id="pageNotesList" notes="[[notes_]]"
      on-all-notes-click="onAllNotesClick_"
      first-note-creation="[[!hasNotesInAnyPages_]]"
      start-note-creation="{{startNoteCreation_}}">
  </user-notes-list>
</template>