[ObjC ARC] Converts ios/web/public/test/fakes:fakes to ARC.

ios/web/public/test/fakes/test_java_script_dialog_presenter.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 IOS_WEB_PUBLIC_TEST_FAKES_TEST_JAVA_SCRIPT_DIALOG_PRESENTER_H_
 #define IOS_WEB_PUBLIC_TEST_FAKES_TEST_JAVA_SCRIPT_DIALOG_PRESENTER_H_
 
 #include <vector>
 
 #import "ios/web/public/java_script_dialog_presenter.h"
-#import "base/mac/scoped_nsobject.h"
 
 namespace web {
 
 struct TestJavaScriptDialog {
   TestJavaScriptDialog();
   TestJavaScriptDialog(const TestJavaScriptDialog&);
   ~TestJavaScriptDialog();
   WebState* web_state = nullptr;
   GURL origin_url;
   JavaScriptDialogType java_script_dialog_type;
-  base::scoped_nsobject<NSString> message_text;
-  base::scoped_nsobject<NSString> default_prompt_text;
+  NSString* message_text;
+  NSString* default_prompt_text;
 };
 
 // Test presenter to check that the JavaScriptDialogPresenter methods are called
 // as expected. |RunJavaScriptDialog| always calls |callback| with
 // |callback_success_argument| and |callback_user_input_argument| values.
 class TestJavaScriptDialogPresenter : public JavaScriptDialogPresenter {
  public:
   TestJavaScriptDialogPresenter();
   ~TestJavaScriptDialogPresenter();
 
@@ skipping 14 matching lines @@
     return requested_dialogs_;
   }
 
   // Sets |success| argument to be used for RunJavaScriptDialog callback.
   void set_callback_success_argument(bool success) {
     callback_success_argument_ = success;
   }
 
   // Sets |user_input| argument to be used for RunJavaScriptDialog callback.
   void set_callback_user_input_argument(NSString* user_input) {
-    callback_user_input_argument_.reset(user_input);
+    callback_user_input_argument_ = user_input;
   }
 
  private:
   bool cancel_dialogs_called_ = false;
   std::vector<TestJavaScriptDialog> requested_dialogs_;
   bool callback_success_argument_ = false;
-  base::scoped_nsobject<NSString> callback_user_input_argument_;
+  NSString* callback_user_input_argument_;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_PUBLIC_TEST_FAKES_TEST_JAVA_SCRIPT_DIALOG_PRESENTER_H_