Handle File.listFiles() returning null on IO errors

chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java

 // Copyright 2014 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.share;
 
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
@@ skipping 101 matching lines @@
             sFakeIntentReceiverForTesting.fireIntent(context, intent);
         } else {
             activity.startActivity(intent);
         }
     }
 
     @SuppressFBWarnings("NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE")
     private static void deleteShareImageFiles(File file) {
         if (!file.exists()) return;
         if (file.isDirectory()) {
-            for (File f : file.listFiles()) deleteShareImageFiles(f);
+            File[] file_list = file.listFiles();
+            if (file_list != null) {
+                for (File f : file_list) deleteShareImageFiles(f);
+            }
         }
         if (!file.delete()) {
             Log.w(TAG, "Failed to delete share image file: %s", file.getAbsolutePath());
         }
     }
 
     /**
      * Force the use of a Chrome-specific intent chooser, not the system chooser.
      *
      * This emulates the behavior on pre Lollipop-MR1 systems, where the system chooser is not
@@ skipping 567 matching lines @@
      */
     @Nullable
     public static ComponentName getLastShareComponentName() {
         SharedPreferences preferences = ContextUtils.getAppSharedPreferences();
         String packageName = preferences.getString(PACKAGE_NAME_KEY, null);
         String className = preferences.getString(CLASS_NAME_KEY, null);
         if (packageName == null || className == null) return null;
         return new ComponentName(packageName, className);
     }
 }