Revert of Fold UpdateModel into UpdateScreen.

chrome/browser/chromeos/login/screens/update_screen.h

Index: chrome/browser/chromeos/login/screens/update_screen.h
diff --git a/chrome/browser/chromeos/login/screens/update_screen.h b/chrome/browser/chromeos/login/screens/update_screen.h
index 2c60ba4ea9237bda0af6bc0d8f7464c57479027b..a3fd36c3555d4f55ce14a26a804e506b80aca749 100644
--- a/chrome/browser/chromeos/login/screens/update_screen.h
+++ b/chrome/browser/chromeos/login/screens/update_screen.h
@@ -14,8 +14,8 @@
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
-#include "chrome/browser/chromeos/login/screens/base_screen.h"
 #include "chrome/browser/chromeos/login/screens/error_screen.h"
+#include "chrome/browser/chromeos/login/screens/update_model.h"
 #include "chromeos/dbus/update_engine_client.h"
 #include "chromeos/network/portal_detector/network_portal_detector.h"
 #include "components/pairing/host_pairing_controller.h"
@@ -30,26 +30,29 @@
 class UpdateView;
 
 // Controller for the update screen.
-class UpdateScreen : public BaseScreen,
+class UpdateScreen : public UpdateModel,
                      public UpdateEngineClient::Observer,
                      public NetworkPortalDetector::Observer {
  public:
-  static UpdateScreen* Get(ScreenManager* manager);
-
-  // Returns true if this instance is still active (i.e. has not been deleted).
-  static bool HasInstance(UpdateScreen* inst);
-
   UpdateScreen(BaseScreenDelegate* base_screen_delegate,
                UpdateView* view,
                pairing_chromeos::HostPairingController* remora_controller);
   ~UpdateScreen() override;
 
-  // Called when the being destroyed. This should call Unbind() on the
-  // associated View if this class is destroyed before it.
-  void OnViewDestroyed(UpdateView* view);
+  static UpdateScreen* Get(ScreenManager* manager);
+
+  // UpdateModel:
+  void Show() override;
+  void Hide() override;
+  void OnViewDestroyed(UpdateView* view) override;
+  void OnUserAction(const std::string& action_id) override;
+  void OnContextKeyUpdated(const ::login::ScreenContext::KeyType& key) override;
 
   // Starts network check. Made virtual to simplify mocking.
   virtual void StartNetworkCheck();
+
+  // Returns true if this instance is still active (i.e. has not been deleted).
+  static bool HasInstance(UpdateScreen* inst);
 
   void SetIgnoreIdleStatus(bool ignore_idle_status);
 
@@ -80,17 +83,12 @@
   FRIEND_TEST_ALL_PREFIXES(UpdateScreenTest, TestUpdateAvailable);
   FRIEND_TEST_ALL_PREFIXES(UpdateScreenTest, TestAPReselection);
 
-  enum class State {
+  enum State {
     STATE_IDLE = 0,
     STATE_FIRST_PORTAL_CHECK,
     STATE_UPDATE,
     STATE_ERROR
   };
-
-  // BaseScreen:
-  void Show() override;
-  void Hide() override;
-  void OnUserAction(const std::string& action_id) override;
 
   // Updates downloading stats (remaining time and downloading
   // progress) on the AU screen.
@@ -130,54 +128,52 @@
   base::OneShotTimer reboot_timer_;
 
   // Returns a static InstanceSet.
-  // TODO(jdufault): There should only ever be one instance of this class.
-  // Remove support for supporting multiple instances. See crbug.com/672142.
   typedef std::set<UpdateScreen*> InstanceSet;
   static InstanceSet& GetInstanceSet();
 
   // Current state of the update screen.
-  State state_ = State::STATE_IDLE;
+  State state_;
 
   // Time in seconds after which we decide that the device has not rebooted
   // automatically. If reboot didn't happen during this interval, ask user to
   // reboot device manually.
-  int reboot_check_delay_ = 0;
+  int reboot_check_delay_;
 
   // True if in the process of checking for update.
-  bool is_checking_for_update_ = true;
+  bool is_checking_for_update_;
   // Flag that is used to detect when update download has just started.
-  bool is_downloading_update_ = false;
+  bool is_downloading_update_;
   // If true, update deadlines are ignored.
   // Note, this is false by default.
-  bool is_ignore_update_deadlines_ = false;
+  bool is_ignore_update_deadlines_;
   // Whether the update screen is shown.
-  bool is_shown_ = false;
+  bool is_shown_;
   // Ignore fist IDLE status that is sent before update screen initiated check.
-  bool ignore_idle_status_ = true;
+  bool ignore_idle_status_;
 
-  UpdateView* view_ = nullptr;
+  UpdateView* view_;
 
   // Used to track updates over Bluetooth.
   pairing_chromeos::HostPairingController* remora_controller_;
 
   // Time of the first notification from the downloading stage.
   base::Time download_start_time_;
-  double download_start_progress_ = 0;
+  double download_start_progress_;
 
   // Time of the last notification from the downloading stage.
   base::Time download_last_time_;
-  double download_last_progress_ = 0;
+  double download_last_progress_;
 
-  bool is_download_average_speed_computed_ = false;
-  double download_average_speed_ = 0;
+  bool is_download_average_speed_computed_;
+  double download_average_speed_;
 
   // True if there was no notification from NetworkPortalDetector
   // about state for the default network.
-  bool is_first_detection_notification_ = true;
+  bool is_first_detection_notification_;
 
   // True if there was no notification about captive portal state for
   // the default network.
-  bool is_first_portal_notification_ = true;
+  bool is_first_portal_notification_;
 
   std::unique_ptr<ErrorScreensHistogramHelper> histogram_helper_;