VR: Render the current URL and security level on the URL bar.

chrome/browser/android/vr_shell/ui_elements/url_bar.h

 // Copyright 2017 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_ELEMENTS_URL_BAR_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_URL_BAR_H_
 
 #include <memory>
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "chrome/browser/android/vr_shell/ui_elements/textured_element.h"
 #include "url/gurl.h"
 
 namespace vr_shell {
 
 class UrlBarTexture;
 
 class UrlBar : public TexturedElement {
  public:
   explicit UrlBar(int preferred_width);
   ~UrlBar() override;
 
   void OnHoverEnter() override;
   void OnHoverLeave() override;
+  void OnButtonUp() override;
+  void SetEnabled(bool enabled);
   void SetURL(const GURL& gurl);
+  void SetSecurityLevel(int level);
+  void SetBackButtonCallback(const base::Callback<void()>& callback);
 
  private:
   UiTexture* GetTexture() const override;
   std::unique_ptr<UrlBarTexture> texture_;
+  base::Callback<void()> back_button_callback_;
+  bool enabled_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(UrlBar);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_URL_BAR_H_