cros: Only preload the lock screen; do not reuse it.

chrome/browser/chromeos/login/lock/webui_screen_locker.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WEBUI_SCREEN_LOCKER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WEBUI_SCREEN_LOCKER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 37 matching lines @@
 class WebUIScreenLocker : public WebUILoginView,
                           public LoginDisplay::Delegate,
                           public ash::LockStateObserver,
                           public views::WidgetObserver,
                           public PowerManagerClient::Observer,
                           public ash::ShellObserver,
                           public keyboard::KeyboardControllerObserver,
                           public display::DisplayObserver,
                           public content::WebContentsObserver {
  public:
-  // Returns true if the lock screen should be shared.
-  static bool ShouldShareLockScreen();
-  static void Preload();
+  // Request lock screen preload when the user is idle. Does nothing if
+  // preloading is disabled or if the preload hueristics return false.
+  static void RequestPreload();
 
   explicit WebUIScreenLocker(ScreenLocker* screen_locker);
   ~WebUIScreenLocker() override;
 
   // Begin initializing the widget and views::WebView that show the lock screen.
   // ScreenLockReady is called when all initialization has finished.
   void LockScreen();
 
   // Enable/disable password input.
   void SetInputEnabled(bool enabled);
@@ skipping 17 matching lines @@
 
   // Called when webui lock screen wallpaper is loaded and displayed.
   void OnLockBackgroundDisplayed();
 
   // Called when the webui header bar becomes visible.
   void OnHeaderBarVisible();
 
  private:
   friend class test::WebUIScreenLockerTester;
 
+  // Returns true if the lock screen should be preloaded.
+  static bool ShouldPreloadLockScreen();
+  // Helper function that creates and preloads a views::WebView.
+  static std::unique_ptr<views::WebView> DoPreload(Profile* profile);
+
   // LoginDisplay::Delegate:
   void CancelPasswordChangedFlow() override;
   void CompleteLogin(const UserContext& user_context) override;
   base::string16 GetConnectedNetworkName() override;
   bool IsSigninInProgress() const override;
   void Login(const UserContext& user_context,
              const SigninSpecifics& specifics) override;
   void MigrateUserData(const std::string& old_password) override;
   void OnSigninScreenReady() override;
   void OnGaiaScreenReady() override;
@@ skipping 43 matching lines @@
 
   // Returns the native window displaying the lock screen.
   gfx::NativeWindow GetNativeWindow() const;
 
   // Ensures that user pod is focused.
   void FocusUserPod();
 
   // Reset user pod and ensures that user pod is focused.
   void ResetAndFocusUserPod();
 
+  // Configuration settings.
+  WebViewSettings BuildConfigSettings();
+
   // The ScreenLocker that owns this instance.
   ScreenLocker* screen_locker_ = nullptr;
 
   // The screen locker window.
   LockWindow* lock_window_ = nullptr;
 
   // Sign-in Screen controller instance (owns login screens).
   std::unique_ptr<SignInScreenController> signin_screen_controller_;
 
   // Login UI implementation instance.
@@ skipping 14 matching lines @@
   bool is_observing_keyboard_ = false;
 
   base::WeakPtrFactory<WebUIScreenLocker> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUIScreenLocker);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_LOCK_WEBUI_SCREEN_LOCKER_H_