🍝🏠 Refactor MostVisited UI management, extract it for reuse in Home.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageViewHolder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageViewHolder.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageViewHolder.java
index 75248d2985e267326054f9450029fadc051da9b3..5af6950cdb255f3d1d22f8c6fc59c7935e6151ae 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageViewHolder.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/NewTabPageViewHolder.java
@@ -7,12 +7,23 @@ package org.chromium.chrome.browser.ntp.cards;
 import android.support.v7.widget.RecyclerView;
 import android.view.View;
 
+import org.chromium.base.Callback;
+
 /**
  * Holds metadata about an item we want to display on the NTP. An item can be anything that will be
  * displayed on the NTP {@link RecyclerView}.
  */
 public class NewTabPageViewHolder extends RecyclerView.ViewHolder {
     /**
+     * A callback to perform a partial bind on a {@link NewTabPageViewHolder}.
+     * @see org.chromium.chrome.browser.ntp.cards.InnerNode#notifyItemChanged(int, Object)
+     */
+    public abstract static class PartialBindCallback extends Callback<NewTabPageViewHolder> {
+        @Override
+        public abstract void onResult(NewTabPageViewHolder holder);
+    }
+
+    /**
      * Constructs a {@link NewTabPageViewHolder} used to display an part of the NTP (e.g., header,
      * article snippet, above-the-fold view, etc.)
      *