Remove null entries from UMA stats SharedPrefs

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java

Index: chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
index c1c51acf18d82e019be567aa41b6f162ad87d114..d70d04daea1d7e139a695b3fb1729cc266905c2c 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
@@ -1602,7 +1602,8 @@ public class DownloadManagerService extends BroadcastReceiver implements
             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);
             }
         }
     }