Remove null entries from UMA stats SharedPrefs

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.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.download;
 
 import android.app.DownloadManager;
 import android.content.ActivityNotFoundException;
 import android.content.BroadcastReceiver;
 import android.content.Context;
@@ skipping 1584 matching lines @@
     }
 
     /**
      * Parse the DownloadUmaStatsEntry from the shared preference.
      */
     private void parseUMAStatsEntriesFromSharedPrefs() {
         if (mSharedPrefs.contains(DOWNLOAD_UMA_ENTRY)) {
             Set<String> entries =
                     DownloadManagerService.getStoredDownloadInfo(mSharedPrefs, DOWNLOAD_UMA_ENTRY);
             for (String entryString : entries) {
-                mUmaEntries.add(DownloadUmaStatsEntry.parseFromString(entryString));
+                DownloadUmaStatsEntry entry = DownloadUmaStatsEntry.parseFromString(entryString);
+                if (entry != null) mUmaEntries.add(entry);
             }
         }
     }
 
     /** Adds a new DownloadHistoryAdapter to the list. */
     @Override
     public void addDownloadHistoryAdapter(DownloadHistoryAdapter adapter) {
         mHistoryAdapters.addObserver(adapter);
         DownloadSharedPreferenceHelper.getInstance().addObserver(adapter);
     }
@@ skipping 207 matching lines @@
             boolean isOffTheRecord);
     private native void nativeRemoveDownload(long nativeDownloadManagerService, String downloadGuid,
             boolean isOffTheRecord);
     private native void nativeGetAllDownloads(
             long nativeDownloadManagerService, boolean isOffTheRecord);
     private native void nativeCheckForExternallyRemovedDownloads(
             long nativeDownloadManagerService, boolean isOffTheRecord);
     private native void nativeUpdateLastAccessTime(
             long nativeDownloadManagerService, String downloadGuid, boolean isOffTheRecord);
 }