Update toast behavior and apperance according to UX requirement

chrome/browser/android/vr_shell/ui_elements/exclusive_screen_toast.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_EXCLUSIVE_SCREEN_TOAST_H_
+#define CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_EXCLUSIVE_SCREEN_TOAST_H_
+
+#include "base/macros.h"
+#include "chrome/browser/android/vr_shell/textures/exclusive_screen_toast_texture.h"
+#include "chrome/browser/android/vr_shell/ui_elements/simple_textured_element.h"
+
+namespace vr_shell {
+
+class ExclusiveScreenToast
+    : public SimpleTexturedElement<ExclusiveScreenToastTexture> {
+ public:
+  explicit ExclusiveScreenToast(int preferred_width);
+  ~ExclusiveScreenToast() override;
+
+ private:
+  void UpdateElementSize() override;
+
+  DISALLOW_COPY_AND_ASSIGN(ExclusiveScreenToast);
+};
+
+}  // namespace vr_shell
+
+#endif  // CHROME_BROWSER_ANDROID_VR_SHELL_UI_ELEMENTS_EXCLUSIVE_SCREEN_TOAST_H_