VR: Add stub WebVR warnings.

chrome/browser/android/vr_shell/ui_scene_manager.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_ANDROID_VR_SHELL_UI_SCENE_MANAGER_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_UI_SCENE_MANAGER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/timer/timer.h"
 #include "base/values.h"
 
 namespace vr_shell {
 
+struct UiElement;
 class UiScene;
 
 class UiSceneManager {
  public:
   explicit UiSceneManager(UiScene* scene);
   ~UiSceneManager();
 
   base::WeakPtr<UiSceneManager> GetWeakPtr();
 
   void UpdateScene(std::unique_ptr<base::ListValue> commands);
 
   void SetWebVRSecureOrigin(bool secure);
   void SetWebVRMode(bool web_vr);
 
  private:
+  void ConfigureSecurityWarnings();
+  void OnSecurityWarningTimer();
+
   UiScene* scene_;
 
+  // UI elemenet pointers (not owned by the scene manager).
+  UiElement* permanent_security_warning_ = nullptr;
+  UiElement* transient_security_warning_ = nullptr;
+
   bool web_vr_mode_ = false;
   bool secure_origin_ = false;
 
+  base::OneShotTimer security_warning_timer_;
+
   base::WeakPtrFactory<UiSceneManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UiSceneManager);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_UI_SCENE_MANAGER_H_