cros: Various fixes needed for preloading lock screen.

chrome/browser/chromeos/login/ui/shared_web_view.h

 // Copyright 2016 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_SHARED_WEB_VIEW_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_UI_SHARED_WEB_VIEW_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 19 matching lines @@
   explicit SharedWebView(Profile* profile);
   ~SharedWebView() override;
   void Shutdown() override;
 
   // Stores a webview instance inside of |out_handle|. |url| is the initial
   // URL that the webview stores (note: this function does not perform the
   // navigation). This returns true if the webview was reused, false if it
   // was freshly created.
   bool Get(const GURL& url, scoped_refptr<WebViewHandle>* out_handle);
 
+  // Returns true if there is an attached views::WebView instance.
+  bool has_web_view() const { return !!web_view_handle_; }
+
  private:
   // content::NotificationObserver:
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
   // Called when there is a memory pressure event.
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel level);
 
@@ skipping 11 matching lines @@
   scoped_refptr<WebViewHandle> web_view_handle_;
 
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 
   DISALLOW_COPY_AND_ASSIGN(SharedWebView);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UI_SHARED_WEB_VIEW_H_