Hide the tab indicators and the shelf when in immersive + tab fullscreen

chrome/browser/fullscreen_chromeos.cc

+// Copyright (c) 2013 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.
+
+#include "chrome/browser/fullscreen.h"
+
+#include "ash/root_window_controller.h"
+#include "ash/wm/window_util.h"
+
+bool IsFullScreenMode() {
+  aura::Window* active_window = ash::wm::GetActiveWindow();
+  if (!active_window)
+    return false;
+  ash::internal::RootWindowController* controller =
+      ash::internal::RootWindowController::ForWindow(active_window);
+  if (!controller)
+    return false;
+
+  return controller->GetFullscreenWindow();
+}