cros: Use ScreenManager as a component instead of deriving WizardController from it

chrome/browser/chromeos/login/wizard_controller.h

 // Copyright (c) 2012 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 CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_CONTROLLER_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 33 matching lines @@
 class LoginDisplayHost;
 class LoginScreenContext;
 class OobeUI;
 class SimpleGeolocationProvider;
 class TimeZoneProvider;
 struct TimeZoneResponseData;
 
 // Class that manages control flow between wizard screens. Wizard controller
 // interacts with screen controllers to move the user between screens.
 class WizardController : public BaseScreenDelegate,
-                         public ScreenManager,
                          public EulaScreen::Delegate,
                          public ControllerPairingScreen::Delegate,
                          public HostPairingScreen::Delegate,
                          public NetworkScreen::Delegate,
                          public HIDDetectionScreen::Delegate {
  public:
   WizardController(LoginDisplayHost* host, OobeUI* oobe_ui);
   ~WizardController() override;
 
   // Returns the default wizard controller if it has been created.
@@ skipping 41 matching lines @@
   // reworked at hackaton.
   void EnableUserImageScreenReturnToPreviousHack();
 
   // Returns a pointer to the current screen or nullptr if there's no such
   // screen.
   BaseScreen* current_screen() const { return current_screen_; }
 
   // Returns true if the current wizard instance has reached the login screen.
   bool login_screen_started() const { return login_screen_started_; }
 
-  // ScreenManager implementation.
-  BaseScreen* GetScreen(OobeScreen screen) override;
-  BaseScreen* CreateScreen(OobeScreen screen) override;
+  // Returns a given screen. Creates it lazily.
+  BaseScreen* GetScreen(OobeScreen screen);
+
+  // Returns the current ScreenManager instance.
+  ScreenManager* screen_manager() { return &screen_manager_; }
 
   // Volume percent at which spoken feedback is still audible.
   static const int kMinAudibleOutputVolumePercent;
 
+  // Allocate a given BaseScreen for the given |Screen|. Used by
+  // |screen_manager_|.
+  BaseScreen* CreateScreen(OobeScreen screen);
+
  private:
   // Show specific screen.
   void ShowNetworkScreen();
   void ShowUpdateScreen();
   void ShowUserImageScreen();
   void ShowEulaScreen();
   void ShowEnrollmentScreen();
   void ShowResetScreen();
   void ShowKioskAutolaunchScreen();
   void ShowEnableDebuggingScreen();
@@ skipping 160 matching lines @@
   void OnSetHostNetworkSuccessful();
   void OnSetHostNetworkFailed();
 
   // Start the enrollment screen using the config from
   // |prescribed_enrollment_config_|. If |force_interactive| is true,
   // the user will be presented with a manual enrollment screen requiring
   // Gaia credentials. If it is false, the screen may return after trying
   // attestation-based enrollment if appropriate.
   void StartEnrollmentScreen(bool force_interactive);
 
+  ScreenManager screen_manager_;
+
   // Whether to skip any screens that may normally be shown after login
   // (registration, Terms of Service, user image selection).
   static bool skip_post_login_screens_;
 
   static bool zero_delay_enabled_;
 
   // Screen that's currently active.
   BaseScreen* current_screen_ = nullptr;
 
   // Screen that was active before, or nullptr for login screen.
@@ skipping 92 matching lines @@
   BaseScreen* hid_screen_ = nullptr;
 
   base::WeakPtrFactory<WizardController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WizardController);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_WIZARD_CONTROLLER_H_