Handle the search box being detached from the NewTabPageView when calculating its offset.

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java

 // Copyright 2015 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;
 
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.content.res.Resources;
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         int searchBoxX = (int) mSearchBoxView.getX();
         int searchBoxY = (int) mSearchBoxView.getY();
 
         bounds.set(searchBoxX + mSearchBoxView.getPaddingLeft(),
                 searchBoxY + mSearchBoxView.getPaddingTop(),
                 searchBoxX + mSearchBoxView.getWidth() - mSearchBoxView.getPaddingRight(),
                 searchBoxY + mSearchBoxView.getHeight() - mSearchBoxView.getPaddingBottom());
 
         translation.set(0, 0);
 
-        View view = (View) mSearchBoxView.getParent();
-        while (view != null) {
+        View view = mSearchBoxView;
+        while (true) {
+            view = (View) view.getParent();
+            if (view == null) {
+                // The |mSearchBoxView| is not a child of this view. This can happen if the
+                // RecyclerView detaches the NewTabPageLayout after it has been scrolled out of
+                // view. Set the translation to the minimum Y value as an approximation.
+                translation.y = Integer.MIN_VALUE;
+                break;
+            }
             translation.offset(-view.getScrollX(), -view.getScrollY());
             if (view == this) break;
             translation.offset((int) view.getX(), (int) view.getY());
-            view = (View) view.getParent();
         }
         bounds.offset(translation.x, translation.y);
     }
 
     /**
      * Sets the listener for search box scroll changes.
      * @param listener The listener to be notified on changes.
      */
     void setSearchBoxScrollListener(OnSearchBoxScrollListener listener) {
         mSearchBoxScrollListener = listener;
@@ skipping 374 matching lines @@
     }
 
     private int getVerticalScroll() {
         if (mUseCardsUi) {
             return mRecyclerView.computeVerticalScrollOffset();
         } else {
             return mScrollView.getScrollY();
         }
     }
 }