ash: Use SessionController instead of SessionStateDelegate

ash/shell/example_session_controller_client.cc

Index: ash/shell/example_session_controller_client.cc
diff --git a/ash/shell/example_session_controller_client.cc b/ash/shell/example_session_controller_client.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bff5dee2a645a7722d4b061045f3a3efd30e8d56
--- /dev/null
+++ b/ash/shell/example_session_controller_client.cc
@@ -0,0 +1,54 @@
+// 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 "ash/shell/example_session_controller_client.h"
+
+#include "ash/shell.h"
+#include "ash/shell/example_factory.h"
+#include "base/logging.h"
+
+namespace ash {
+namespace shell {
+
+namespace {
+
+ExampleSessionControllerClient* instance = nullptr;
+
+}  // namespace
+
+ExampleSessionControllerClient::ExampleSessionControllerClient(
+    SessionController* controller)
+    : TestSessionControllerClient(controller) {
+  DCHECK_EQ(instance, nullptr);

[James Cook, 2017/03/17 17:14:36]

nit: Also DCHECK(controller)

[xiyuan, 2017/03/17 22:52:03]

Done.

+  instance = this;
+}
+
+ExampleSessionControllerClient::~ExampleSessionControllerClient() {
+  DCHECK_EQ(instance, this);
+  instance = nullptr;
+}
+
+// static
+ExampleSessionControllerClient* ExampleSessionControllerClient::Get() {
+  return instance;
+}
+
+void ExampleSessionControllerClient::Initialize() {
+  // ash_shell has 2 users.
+  SetPredefinedUserSessions(2);
+}
+
+void ExampleSessionControllerClient::RequestLockScreen() {
+  TestSessionControllerClient::RequestLockScreen();
+  shell::CreateLockScreen();
+  Shell::GetInstance()->UpdateShelfVisibility();
+}
+
+void ExampleSessionControllerClient::UnlockScreen() {
+  TestSessionControllerClient::UnlockScreen();
+  Shell::GetInstance()->UpdateShelfVisibility();
+}
+
+}  // namespace shell
+}  // namespace ash