Add the supporting code for the cast system tray integration

ash/cast_config_delegate.cc

Index: ash/cast_config_delegate.cc
diff --git a/ash/cast_config_delegate.cc b/ash/cast_config_delegate.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5cbbc07b21e5fb3e55dd55b04b1caada29724dc9
--- /dev/null
+++ b/ash/cast_config_delegate.cc
@@ -0,0 +1,27 @@
+// 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.
+
+#include "ash/cast_config_delegate.h"
+
+namespace ash {
+
+CastConfigDelegate::Receiver::Receiver() {
+}
+
+CastConfigDelegate::Receiver::~Receiver() {
+}
+
+CastConfigDelegate::Activity::Activity() {
+}
+
+CastConfigDelegate::Activity::~Activity() {
+}
+
+CastConfigDelegate::ReceiverAndActivity::ReceiverAndActivity() {
+}
+
+CastConfigDelegate::ReceiverAndActivity::~ReceiverAndActivity() {
+}
+
+}  // namespace ash