[NTP Snippets] Make a base::Feature instead of raw cmdline flag

chrome/android/java/src/org/chromium/chrome/browser/ChromeSwitches.java

 // 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.
 
 package org.chromium.chrome.browser;
 
 /**
  * Contains all of the command line switches that are specific to the chrome/
  * portion of Chromium on Android.
  */
@@ skipping 71 matching lines @@
      * Disable bottom infobar-like Reader Mode panel.
      */
     public static final String DISABLE_READER_MODE_BOTTOM_BAR = "disable-reader-mode-bottom-bar";
 
     /**
      * Disable Lo-Fi snackbar.
      */
     public static final String DISABLE_LOFI_SNACKBAR = "disable-lo-fi-snackbar";
 
     /**
-     * Enable content snippets on the NTP
-     */
-    public static final String ENABLE_NTP_SNIPPETS = "enable-ntp-snippets";
-
-    /**
      * Enable interests on the NTP
      */
     public static final String ENABLE_INTERESTS = "enable-interests";
 
     /**
      * Forces the update menu item to show.
      */
     public static final String FORCE_SHOW_UPDATE_MENU_ITEM = "force-show-update-menu-item";
 
     /**
@@ skipping 133 matching lines @@
 
     /**
      * Enable tab switcher in document mode (merged tabs and apps option).
      */
     public static final String ENABLE_TAB_SWITCHER_IN_DOCUMENT_MODE =
             "enable-tab-switcher-in-document-mode";
 
     // Prevent instantiation.
     private ChromeSwitches() {}
 }