Add kApplicationIdKey for ShellSurface::GetApplicationId and SetApplicationId

chrome/browser/ui/ash/launcher/arc_app_window_launcher_controller.cc

 // 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.
 #include "chrome/browser/ui/ash/launcher/arc_app_window_launcher_controller.h"
 
 #include <string>
 
 #include "ash/display/screen_orientation_controller_chromeos.h"
 #include "ash/public/cpp/window_properties.h"
 #include "ash/shared/app_types.h"
@@ skipping 712 matching lines @@
     }
   }
   ash::Shell* shell = ash::Shell::Get();
   shell->screen_orientation_controller()->LockOrientationForWindow(
       window, BlinkOrientationLockFromMojom(orientation_lock),
       lock_completion_behavior);
 }
 
 // static
 int ArcAppWindowLauncherController::GetWindowTaskId(aura::Window* window) {
-  const std::string arc_app_id = exo::ShellSurface::GetApplicationId(window);
-  if (arc_app_id.empty())
+  const std::string* arc_app_id = exo::ShellSurface::GetApplicationId(window);
+  if (!arc_app_id)
     return -1;
 
   int task_id = -1;
-  if (sscanf(arc_app_id.c_str(), "org.chromium.arc.%d", &task_id) != 1)
+  if (sscanf(arc_app_id->c_str(), "org.chromium.arc.%d", &task_id) != 1)
     return -1;
 
   return task_id;
 }