Tentative fix for scroll event related crashes on the NTP

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
index 33cf29924015c9079503ea1637b8e3f1cc23f9d2..3f244fd119f6f155560c253a1cdcac3d8612c687 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java
@@ -300,6 +300,12 @@ void ensureIconIsAvailable(String pageUrl, String iconUrl, boolean isLargeIcon,
          * Page goes away.
          */
         void registerSignInStateObserver(SignInStateObserver signInStateObserver);
+
+        /**
+         * @return whether the {@link NewTabPage} associated with this manager is the current page
+         * displayed to the user.
+         */
+        boolean isCurrentPage();
     }
 
     /**
@@ -491,6 +497,12 @@ public void onClick(View v) {
     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;
+
         if (mSearchBoxScrollListener != null) {
             mSearchBoxScrollListener.onNtpScrollChanged(getToolbarTransitionPercentage());
         }