chrome/android/java/res/drawable-v23/section_tab_background.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright 2022 The Chromium Authors. All rights reserved.
     Use of this source code is governed by a BSD-style license that can be
     found in the LICENSE file. -->

<selector xmlns:android="http://schemas.android.com/apk/res/android">
  <item android:state_selected="false">
    <shape
        android:shape="rectangle">
      <corners android:radius="@dimen/section_tab_background_corner_radius" />
      <solid android:color="@color/section_header_bg_color_baseline"/>
    </shape>
  </item>
  <item android:state_selected="true">
    <shape
        android:shape="rectangle">
      <corners android:radius="@dimen/section_tab_background_corner_radius" />
      <stroke android:width="@dimen/section_tab_bezel_width" android:color="@android:color/transparent" />
      <solid android:color="@color/section_header_active_tab_bg_color_baseline"/>
    </shape>
  </item>
</selector>