chromium/chrome/browser/resources/extensions/activity_log/activity_log_stream.html

<style include="shared-style">
  :host {
    --activity-log-call-and-time-width: 575px;
    --activity-type-width: 85px;
    --activity-time-width: 100px;

    display: flex;
    flex-direction: column;
  }

  cr-search-field {
    align-self: center;
    margin-inline-end: auto;
  }

  .activity-table-headings {
    width: var(--activity-log-call-and-time-width);
  }

  #activity-type {
    flex: 0 var(--activity-type-width);
  }

  #activity-key {
    flex: 1;
    margin-inline-start: 10px;
  }

  #activity-time {
    flex: 0 var(--activity-time-width);
    text-align: end;
  }

  iron-list {
    flex: 1;
  }
</style>
<div class="activity-subpage-header">
  <cr-search-field label="$i18n{activityLogSearchLabel}"
    on-search-changed="onSearchChanged_">
  </cr-search-field >
  <cr-button id="toggle-stream-button" on-click="onToggleButtonClick_">
    <span hidden$="[[isStreamOn_]]">
      $i18n{startActivityStream}
    </span>
    <span hidden$="[[!isStreamOn_]]">
      $i18n{stopActivityStream}
    </span>
  </cr-button>
  <cr-button class="clear-activities-button" on-click="clearStream">
    $i18n{clearActivities}
  </cr-button>
</div>
<div id="empty-stream-message" class="activity-message"
    hidden$="[[!isStreamEmpty_(activityStream_.length)]]">
  <span id="stream-stopped-message" hidden$="[[isStreamOn_]]">
    $i18n{emptyStreamStopped}
  </span>
  <span id="stream-started-message" hidden$="[[!isStreamOn_]]">
    $i18n{emptyStreamStarted}
  </span>
</div>
<div id="empty-search-message" class="activity-message"
    hidden$="[[!shouldShowEmptySearchMessage_(
        activityStream_.length, filteredActivityStream_.length)]]">
  $i18n{noSearchResults}
</div>
<div class="activity-table-headings"
    hidden$="[[isFilteredStreamEmpty_(filteredActivityStream_.length)]]">
  <span id="activity-type">$i18n{activityLogTypeColumn}</span>
  <span id="activity-key">$i18n{activityLogNameColumn}</span>
  <span id="activity-time">$i18n{activityLogTimeColumn}</span>
</div>
<iron-list items="[[filteredActivityStream_]]">
  <template>
    <activity-log-stream-item data="[[item]]"></activity-log-stream-item>
  </template>
</iron-list>