Add new NTP layout with snippet cards and hide it behind a flag

chrome/android/java/res/values-sw600dp/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>
     <!-- Menu Dimensions -->
     <!-- Necessary to align the menu icon with the actual button. -->
     <dimen name="menu_negative_software_vertical_offset">6dp</dimen>
 
@@ skipping 22 matching lines @@
     <dimen name="custom_tabs_control_container_height">64dp</dimen>
 
     <!-- The combined height of the tab strip and toolbar. -->
     <dimen name="tab_strip_and_toolbar_height">96dp</dimen>
 
     <dimen name="location_bar_url_text_size">18sp</dimen>
     <dimen name="location_bar_icon_width">40dp</dimen>
 
     <!-- NTP dimensions -->
     <dimen name="ntp_logo_height">180dp</dimen>
-    <dimen name="snippets_thumbnail_size">120dp</dimen>
 
     <!-- Recent tabs page -->
     <dimen name="recent_tabs_visible_separator_padding">28dp</dimen>
 
     <!-- Omnibox suggestion list -->
     <dimen name="omnibox_suggestion_list_padding_top">8dp</dimen>
     <dimen name="omnibox_suggestion_list_padding_bottom">8dp</dimen>
 
     <!-- Web app dimensions -->
     <dimen name="webapp_splash_offset">48dp</dimen>
     <dimen name="webapp_splash_large_title_margin_bottom">8dp</dimen>
 </resources>