Prompt user for file access permission before download starts

content/public/browser/android/download_controller_android.cc

Index: content/public/browser/android/download_controller_android.cc
diff --git a/content/public/browser/android/download_controller_android.cc b/content/public/browser/android/download_controller_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..fc5f82e0172d2d77fceea54ad8e0483c2c19db46
--- /dev/null
+++ b/content/public/browser/android/download_controller_android.cc
@@ -0,0 +1,13 @@
+// Copyright (c) 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.
+
+#include "content/public/browser/android/download_controller_android.h"
+
+namespace content {
+
+// static
+DownloadControllerAndroid* DownloadControllerAndroid::download_controller_ =
+    nullptr;
+
+}  // namespace content