[remoting android] Add and build host code.

remoting/host/curtain_mode_android.cc

+// Copyright 2016 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 "base/logging.h"
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "remoting/host/curtain_mode.h"
+
+namespace remoting {
+
+namespace {
+
+class CurtainModeAndroid : public CurtainMode {
+ public:
+  CurtainModeAndroid() {}
+
+  // Overriden from CurtainMode.
+  bool Activate() override {
+    NOTIMPLEMENTED();
+    return false;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CurtainModeAndroid);
+};
+
+}  // namespace
+
+// static
+std::unique_ptr<CurtainMode> CurtainMode::Create(
+    scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
+    base::WeakPtr<ClientSessionControl> client_session_control) {
+  return base::WrapUnique(new CurtainModeAndroid());
+}
+
+}  // namespace remoting