Ntp: use callbacks for partial binding, they can carry more detail.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/ChildNode.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/ChildNode.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/ChildNode.java
index 585082cae81fa136d22d1f02e963ac3ae35ebb1f..69e98bbf2279e74fd91842ef1309478cf1f287c6 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/ChildNode.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/cards/ChildNode.java
@@ -5,6 +5,9 @@
 package org.chromium.chrome.browser.ntp.cards;
 
 import android.support.annotation.CallSuper;
+import android.support.annotation.Nullable;
+
+import org.chromium.chrome.browser.ntp.cards.NewTabPageViewHolder.PartialBindCallback;
 
 /**
  * A node in the tree that has a parent and can notify it about changes.
@@ -35,8 +38,9 @@ public abstract class ChildNode implements TreeNode {
         return mNumItems;
     }
 
-    protected void notifyItemRangeChanged(int index, int count, Object payload) {
-        if (mParent != null) mParent.onItemRangeChanged(this, index, count, payload);
+    protected void notifyItemRangeChanged(
+            int index, int count, @Nullable PartialBindCallback callback) {
+        if (mParent != null) mParent.onItemRangeChanged(this, index, count, callback);
     }
 
     protected void notifyItemRangeChanged(int index, int count) {
@@ -55,8 +59,8 @@ public abstract class ChildNode implements TreeNode {
         if (mParent != null) mParent.onItemRangeRemoved(this, index, count);
     }
 
-    protected void notifyItemChanged(int index, Object payload) {
-        notifyItemRangeChanged(index, 1, payload);
+    protected void notifyItemChanged(int index, @Nullable PartialBindCallback callback) {
+        notifyItemRangeChanged(index, 1, callback);
     }
 
     protected void notifyItemChanged(int index) {