Add icon to the Data Saver main menu footer and update to spec

chrome/android/java/res/values/dimens.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Copyright 2014 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. -->
 
 <resources>
     <!-- Connection info popup dimensions -->
     <dimen name="connection_info_padding_wide">24dp</dimen>
     <dimen name="connection_info_padding_thin">16dp</dimen>
 
@@ skipping 127 matching lines @@
     <dimen name="promo_dialog_illustration_margin">24dp</dimen>
     <dimen name="promo_dialog_illustration_width">150dp</dimen>
     <dimen name="promo_dialog_padding">16dp</dimen>
     <dimen name="promo_dialog_max_width">600dp</dimen>
     <dimen name="promo_dialog_max_content_width">320dp</dimen>
     <dimen name="promo_dialog_title_text_size">23sp</dimen>
     <dimen name="promo_dialog_normal_text_size">14sp</dimen>
 
     <!-- Data Saver -->
     <dimen name="data_usage_chart_height">252dp</dimen>
+    <dimen name="data_reduction_main_menu_icon_width">32dp</dimen>
 
     <!-- The size of the text for tab titles. -->
     <dimen name="compositor_tab_title_text_size">13sp</dimen>
     <!-- The size of the bounding box for favicons. -->
     <dimen name="compositor_tab_title_favicon_size">16dp</dimen>
     <!-- Slop value for allowing slight misses on the compositor button. -->
     <dimen name="compositor_button_slop">10dp</dimen>
 
     <!-- User Picture Dimensions -->
     <dimen name="user_picture_size">40dp</dimen>
@@ skipping 285 matching lines @@
     <!--  Miscellaneous dimensions -->
     <dimen name="action_bar_shadow_height">10dp</dimen>
     <dimen name="card_corner_radius">2dp</dimen>
     <dimen name="list_item_corner_radius">3dp</dimen>
     <dimen name="list_item_lateral_padding">1dp</dimen>
     <dimen name="history_default_text_margin">16dp</dimen>
 
     <!-- Context Menu Dimensions -->
     <dimen name="context_menu_header_image_min_size">56dp</dimen>
     <dimen name="context_menu_header_image_max_size">56dp</dimen>
+    
+    <!-- Divider Dimensions -->
+    <dimen name="divider_height">1dp</dimen>
 </resources>