Add ContentVideoViewOverlay to AVDA.

media/base/android/android_overlay.cc

Index: media/base/android/android_overlay.cc
diff --git a/media/base/android/android_overlay.cc b/media/base/android/android_overlay.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3f705ee54fb1b9e71eee41c4b2ff5a58efdc57fe
--- /dev/null
+++ b/media/base/android/android_overlay.cc
@@ -0,0 +1,13 @@
+// Copyright 2017 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 "media/base/android/android_overlay.h"
+
+namespace media {
+
+AndroidOverlay::Config::Config() = default;
+AndroidOverlay::Config::Config(const AndroidOverlay::Config&) = default;
+AndroidOverlay::Config::~Config() = default;
+
+}  // namespace media