Remove all uses of toolkit_use_gtk in the gyp files.

chrome/browser/extensions/api/app_window/app_window_apitest.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 "apps/app_window.h"
 #include "apps/app_window_registry.h"
 #include "apps/ui/native_app_window.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/apps/app_browsertest_util.h"
 #include "chrome/browser/extensions/extension_test_message_listener.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/extensions/features/feature_channel.h"
 #include "chrome/test/base/testing_profile.h"
 #include "ui/base/base_window.h"
 #include "ui/gfx/rect.h"
 
-#ifdef TOOLKIT_GTK
-#include "content/public/test/test_utils.h"
-#endif
-
 using apps::AppWindow;
 
 namespace {
 
 class TestAppWindowRegistryObserver : public apps::AppWindowRegistry::Observer {
  public:
   explicit TestAppWindowRegistryObserver(Profile* profile)
       : profile_(profile), icon_updates_(0) {
     apps::AppWindowRegistry::Get(profile_)->AddObserver(this);
   }
@@ skipping 76 matching lines @@
   EXPECT_TRUE(RunPlatformAppTest(
       "platform_apps/windows_api_always_on_top/no_permissions")) << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, WindowsApiGet) {
   EXPECT_TRUE(RunPlatformAppTest("platform_apps/windows_api_get"))
       << message_;
 }
 
 }  // namespace extensions