Add VR gradient and grid background to non-WebVR scene.

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 SetWebVRSecureOrigin(bool secure);
   void SetWebVRMode(bool web_vr);
 
  private:
+  void CreateSecurityWarnings();
+  void CreateContentQuad();
+  void CreateBackground();
+
   void ConfigureSecurityWarnings();
   void OnSecurityWarningTimer();
-  void OnGLInitialized();
+  int AllocateId();
 
   UiScene* scene_;
 
   // UI element pointers (not owned by the scene manager).
   UiElement* permanent_security_warning_ = nullptr;
   UiElement* transient_security_warning_ = nullptr;
   UiElement* main_content_ = nullptr;
 
   bool web_vr_mode_ = false;
   bool secure_origin_ = false;
 
+  int next_available_id_ = 1;
+
+  std::vector<UiElement*> browser_ui_elements_;
+
   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_