[Android NTP] Move suggestion sections into a separate node.

chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/Leaf.java

 // Copyright 2016 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.ntp.cards;
 
 import org.chromium.chrome.browser.ntp.snippets.SnippetArticle;
 
 /**
  * A permanent leaf in the tree, i.e. a single item.
@@ skipping 24 matching lines @@
         if (position != 0) throw new IndexOutOfBoundsException();
 
         return null;
     }
 
     @Override
     public int getDismissSiblingPosDelta(int position) {
         return 0;
     }
 
+    @Override
+    public void init() {}
+
     /**
      * Display the data for this item.
      * @param holder The view holder that should be updated.
      * @see #onBindViewHolder(NewTabPageViewHolder, int)
      * @see android.support.v7.widget.RecyclerView.Adapter#onBindViewHolder
      */
     protected abstract void onBindViewHolder(NewTabPageViewHolder holder);
 
     /**
      * @return The view type of this item.
      * @see android.support.v7.widget.RecyclerView.Adapter#getItemViewType
      */
     @ItemViewType
     protected abstract int getItemViewType();
 }