Make launching apps from shelf more intuitive

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

 // Copyright (c) 2012 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/app_shortcut_launcher_item_controller.h"
 
 #include <stddef.h>
 
 #include <utility>
 
+#include "ash/root_window_controller.h"
+#include "ash/shell.h"
 #include "ash/wm/window_util.h"
 #include "base/memory/ptr_util.h"
 #include "chrome/browser/extensions/launch_util.h"
 #include "chrome/browser/ui/app_list/arc/arc_app_utils.h"
 #include "chrome/browser/ui/ash/launcher/arc_playstore_shortcut_launcher_item_controller.h"
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_controller.h"
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_controller_util.h"
 #include "chrome/browser/ui/ash/launcher/launcher_context_menu.h"
 #include "chrome/browser/ui/ash/launcher/launcher_controller_helper.h"
 #include "chrome/browser/ui/ash/multi_user/multi_user_util.h"
@@ skipping 86 matching lines @@
     // which take a lot of time for pre-processing (like the files app) before
     // they open a window. Since there is currently no other way to detect if an
     // app was started we suppress any further clicks within a special time out.
     if (IsV2App() && !AllowNextLaunchAttempt()) {
       std::move(callback).Run(
           ash::SHELF_ACTION_NONE,
           GetAppMenuItems(event ? event->flags() : ui::EF_NONE));
       return;
     }
 
+    aura::Window* root_window =
+        ash::Shell::Get()
+            ->GetRootWindowControllerWithDisplayId(display_id)
+            ->GetRootWindow();
+
     // Launching some items replaces this item controller instance, which
     // destroys its ShelfID string pair; making copies avoid crashes.
-    ChromeLauncherController::instance()->LaunchApp(ash::ShelfID(shelf_id()),
-                                                    source, ui::EF_NONE);
+    ChromeLauncherController::instance()->LaunchApp(
+        ash::ShelfID(shelf_id()), source, ui::EF_NONE, root_window);
     std::move(callback).Run(ash::SHELF_ACTION_NEW_WINDOW_CREATED,
                             base::nullopt);
     return;
   }
 
   const ash::ShelfAction action = ActivateContent(content);
   std::move(callback).Run(
       action, GetAppMenuItems(event ? event->flags() : ui::EF_NONE));
 }
 
@@ skipping 232 matching lines @@
 
 bool AppShortcutLauncherItemController::AllowNextLaunchAttempt() {
   if (last_launch_attempt_.is_null() ||
       last_launch_attempt_ + base::TimeDelta::FromMilliseconds(
           kClickSuppressionInMS) < base::Time::Now()) {
     last_launch_attempt_ = base::Time::Now();
     return true;
   }
   return false;
 }