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

chrome/browser/chromeos/login/ui/webui_login_view.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_UI_WEBUI_LOGIN_VIEW_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_UI_WEBUI_LOGIN_VIEW_H_
 
 #include <map>
 #include <string>
 
@@ skipping 16 matching lines @@
 
 namespace views {
 class View;
 class WebView;
 class Widget;
 }
 
 namespace chromeos {
 
 class OobeUI;
-class WebViewHandle;
 
 // View used to render a WebUI supporting Widget. This widget is used for the
 // WebUI based start up and lock screens. It contains a WebView.
 class WebUILoginView : public views::View,
                        public content::WebContentsDelegate,
                        public content::NotificationObserver,
                        public ChromeWebModalDialogManagerDelegate,
                        public web_modal::WebContentsModalDialogHost {
  public:
   struct WebViewSettings {
-    // URL of the WebView to preload and reuse across WebUILoginView instances.
-    GURL preloaded_url;
+    // If true, this will check for and consume a preloaded views::WebView
+    // instance.
+    bool check_for_preload;

[achuithb, 2017/01/13 20:57:52]

should this be initialized to false?

[jdufault, 2017/01/13 22:12:28]

Done.

 
     // Title of the web contents. This will be shown in the task manager. If
     // empty, the default webview title will be used.
     base::string16 web_view_title;
   };
 
   // Internal class name.
   static const char kViewClassName[];
 
   explicit WebUILoginView(const WebViewSettings& settings);
@@ skipping 97 matching lines @@
   // 1. Emits LoginPromptVisible signal if needed
   // 2. Notifies OOBE/sign classes.
   void OnLoginPromptVisible();
 
   content::NotificationRegistrar registrar_;
 
   // WebView configuration options.
   const WebViewSettings settings_;
 
   // WebView for rendering a webpage as a webui login.
-  scoped_refptr<WebViewHandle> webui_login_;
+  std::unique_ptr<views::WebView> webui_login_;
 
   // True if the current webview instance (ie, GetWebUI()) has been reused.
   bool is_reusing_webview_ = false;
 
   // Converts keyboard events on the WebContents to accelerators.
   views::UnhandledKeyboardEventHandler unhandled_keyboard_event_handler_;
 
   // Maps installed accelerators to OOBE webui accelerator identifiers.
   AccelMap accel_map_;
 
@@ skipping 22 matching lines @@
   std::unique_ptr<CycleFocusTraversable> cycle_focus_traversable_;
 
   base::ObserverList<web_modal::ModalDialogHostObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUILoginView);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UI_WEBUI_LOGIN_VIEW_H_