Update enabled state of the NTP search box whenever its alpha changes.

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;
@@ skipping 507 matching lines @@
 
     private void updateSearchBoxOnScroll() {
         if (mDisableUrlFocusChangeAnimations) return;
 
         // When the page changes (tab switching or new page loading), it is possible that events
         // (e.g. delayed RecyclerView change notifications) trigger calls to these methods after
         // the current page changes. We check it again to make sure we don't attempt to update the
         // wrong page.
         if (!mManager.isCurrentPage()) return;
 
-        // Disable the search box contents if it is the process of being animated away.
-        ViewUtils.setEnabledRecursive(mSearchBoxView, mSearchBoxView.getAlpha() == 1.0f);
-
         if (mSearchBoxScrollListener != null) {
             mSearchBoxScrollListener.onNtpScrollChanged(getToolbarTransitionPercentage());
         }
     }
 
     /**
      * Calculates the percentage (between 0 and 1) of the transition from the search box to the
      * omnibox at the top of the New Tab Page, which is determined by the amount of scrolling and
      * the position of the search box.
      *
@@ skipping 262 matching lines @@
         mNewTabPageLayout.setTranslationY(percent * (basePosition - target));
     }
 
     /**
      * Updates the opacity of the search box when scrolling.
      *
      * @param alpha opacity (alpha) value to use.
      */
     public void setSearchBoxAlpha(float alpha) {
         mSearchBoxView.setAlpha(alpha);
+
+        // Disable the search box contents if it is the process of being animated away.
+        ViewUtils.setEnabledRecursive(mSearchBoxView, mSearchBoxView.getAlpha() == 1.0f);
     }
 
     /**
      * Updates the opacity of the search provider logo when scrolling.
      *
      * @param alpha opacity (alpha) value to use.
      */
     public void setSearchProviderLogoAlpha(float alpha) {
         mSearchProviderLogoView.setAlpha(alpha);
     }
@@ skipping 435 matching lines @@
     }
 
     /**
      * @return The adapter position the user has scrolled to.
      */
     public int getScrollPosition() {
         if (mUseCardsUi) return mRecyclerView.getScrollPosition();
         return RecyclerView.NO_POSITION;
     }
 }