Fix MaximizeModeController startup race

ash/wm/maximize_mode/maximize_mode_controller_unittest.cc

 // Copyright 2014 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/common/wm/maximize_mode/maximize_mode_controller.h"
 
 #include <math.h>
 #include <utility>
 #include <vector>
 
 #include "ash/common/ash_switches.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/test/test_system_tray_delegate.h"
 #include "ash/common/wm/overview/window_selector_controller.h"
 #include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "base/command_line.h"
+#include "base/run_loop.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/test/user_action_tester.h"
 #include "chromeos/accelerometer/accelerometer_reader.h"
 #include "chromeos/accelerometer/accelerometer_types.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/fake_power_manager_client.h"
 #include "ui/display/manager/display_manager.h"
 #include "ui/display/test/display_manager_test_api.h"
 #include "ui/events/event_handler.h"
 #include "ui/events/test/event_generator.h"
 #include "ui/gfx/geometry/vector3d_f.h"
 #include "ui/message_center/message_center.h"
 
 #if defined(USE_X11)
 #include "ui/events/test/events_test_utils_x11.h"
 #endif
@@ skipping 543 matching lines @@
         kAccelerometerVerticalHingeUnstableAnglesTestData[i * 6 + 3],
         kAccelerometerVerticalHingeUnstableAnglesTestData[i * 6 + 4],
         kAccelerometerVerticalHingeUnstableAnglesTestData[i * 6 + 5]);
     TriggerBaseAndLidUpdate(base, lid);
     // There are a lot of samples, so ASSERT rather than EXPECT to only generate
     // one failure rather than potentially hundreds.
     ASSERT_TRUE(IsMaximizeModeStarted());
   }
 }
 
+// Tests that when a MaximizeModeController is created that cached tablet mode
+// state will trigger a mode update.
+TEST_F(MaximizeModeControllerTest, InitializedWhileTabletModeSwitchOn) {
+  base::RunLoop().RunUntilIdle();
+  // FakePowerManagerClient is always installed for tests
+  chromeos::FakePowerManagerClient* power_manager_client =
+      static_cast<chromeos::FakePowerManagerClient*>(
+          chromeos::DBusThreadManager::Get()->GetPowerManagerClient());
+  power_manager_client->set_tablet_mode(
+      chromeos::PowerManagerClient::TabletMode::ON);
+  MaximizeModeController controller;
+  EXPECT_FALSE(controller.IsMaximizeModeWindowManagerEnabled());
+  // PowerManagerClient callback is a posted task.
+  base::RunLoop().RunUntilIdle();
+  EXPECT_TRUE(controller.IsMaximizeModeWindowManagerEnabled());
+}
+
 }  // namespace ash