Clear browsing data ui fixes

chrome/android/java/res/layout/clear_browsing_data_tab_content.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2017 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. -->
 
 <!-- Used by ClearBrowsingDataPreferencesTab to replace the default layout
      of a PreferenceFragment and add a footer button. -->
 
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical">
 
     <ListView
         android:id="@android:id/list"
         android:layout_width="match_parent"
         android:layout_weight="1"
         android:layout_height="0dp"/>
 
     <View style="@style/Divider"/>
 
     <Button
         android:id="@+id/clear_button"
         android:layout_gravity="end"
         style="?android:attr/buttonBarButtonStyle"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:padding="8dp"
         android:minHeight="48dp"
-        android:layout_marginEnd="8dp"
+        android:layout_marginEnd="@dimen/clear_browsing_data_button_margin"
         android:focusable="true"
         android:text="@string/clear_data_delete" />
 
 </LinearLayout>