chromium/chrome/android/java/res/drawable/target_view_outline.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
Copyright 2023 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" >
  <stroke
    android:width="@dimen/target_view_stroke_width"/>
  <solid android:color="@color/target_view_color_list" />
  <corners android:radius="@dimen/tab_grid_dialog_bg_radius" />
</shape>