[vr] Introduce VrTabHelper

chrome/browser/android/vr_shell/vr_tab_helper.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_VR_TAB_HELPER_H_
+#define CHROME_BROWSER_ANDROID_VR_SHELL_VR_TAB_HELPER_H_
+
+#include "base/macros.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+namespace vr_shell {
+
+class VrTabHelper : public content::WebContentsUserData<VrTabHelper> {
+ public:
+  ~VrTabHelper() override;
+
+  bool is_in_vr() const { return is_in_vr_; }
+
+  // Called by VrShell when we enter and exit vr mode. It finds us by looking us
+  // up on the WebContents. Eventually, we will also set a number of flags here
+  // as we enter and exit vr mode (see TODO below).
+  void SetIsInVr(bool is_in_vr);
+
+  static bool IsInVr(content::WebContents* contents);
+
+ private:
+  friend class content::WebContentsUserData<VrTabHelper>;
+
+  explicit VrTabHelper(content::WebContents* contents);
+
+  // TODO(asimjour): once we have per-dialog flags for disabling specific
+  // content-related popups, we should hang onto a pointer to the web contents
+  // and set those flags as we enter and exit vr mode.
+  bool is_in_vr_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(VrTabHelper);
+};
+
+}  // namespace vr_shell
+
+#endif  // CHROME_BROWSER_ANDROID_VR_SHELL_VR_TAB_HELPER_H_