mustash: Convert TraySupervisedUserTest to AshTest

ash/common/test/test_system_tray_delegate.h

 // Copyright 2013 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.
 
 #ifndef ASH_COMMON_TEST_TEST_SYSTEM_TRAY_DELEGATE_H_
 #define ASH_COMMON_TEST_TEST_SYSTEM_TRAY_DELEGATE_H_
 
 #include "ash/common/system/tray/default_system_tray_delegate.h"
 #include "ash/common/system/tray/ime_info.h"
 #include "base/macros.h"
 #include "base/time/time.h"
 
 namespace ash {
 namespace test {
 
 class TestSystemTrayDelegate : public DefaultSystemTrayDelegate {
  public:
   TestSystemTrayDelegate();
   ~TestSystemTrayDelegate() override;
 
   // Sets whether a system update is required. Defaults to false. Static so
   // tests can set the value before the system tray is constructed. Reset in
   // AshTestHelper::TearDown.
   static void SetSystemUpdateRequired(bool required);
 
-  // Changes the login status when initially the delegate is created. This will
-  // be called before AshTestBase::SetUp() to test the case when chrome is
-  // restarted right after the login (such like a flag is set).
-  // This value will be reset in AshTestHelper::TearDown,  most test fixtures
-  // don't need to care its lifecycle.
-  static void SetInitialLoginStatus(LoginStatus login_status);
-
   // Changes the current login status in the test. This also invokes
   // UpdateAfterLoginStatusChange(). Usually this is called in the test code to
   // set up a login status. This will fit to most of the test cases, but this
   // cannot be set during the initialization. To test the initialization,
   // consider using SetInitialLoginStatus() instead.
   void SetLoginStatus(LoginStatus login_status);
 
   // Updates the session length limit so that the limit will come from now in
   // |new_limit|.
   void SetSessionLengthLimitForTest(const base::TimeDelta& new_limit);
@@ skipping 20 matching lines @@
  private:
   LoginStatus login_status_;
   base::TimeDelta session_length_limit_;
   bool session_length_limit_set_;
   IMEInfo current_ime_;
   IMEInfoList ime_list_;
 
   DISALLOW_COPY_AND_ASSIGN(TestSystemTrayDelegate);
 };
 
+// Changes the initial login status before TestSystemTrayDelegate is created.
+// Allows testing the case when chrome is restarted right after login (such as a

[msw, 2016/10/14 16:10:29]

nit: "such as when a flag is set" or some better wording.

[James Cook, 2016/10/14 16:32:53]

Done.

+// flag is set).
+class ScopedInitialLoginStatus {
+ public:
+  explicit ScopedInitialLoginStatus(LoginStatus status);
+  ~ScopedInitialLoginStatus();
+
+ private:
+  LoginStatus old_status_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedInitialLoginStatus);
+};
+
 }  // namespace test
 }  // namespace ash
 
 #endif  // ASH_COMMON_TEST_TEST_SYSTEM_TRAY_DELEGATE_H_