[ios] Made TestWebStateDelegate and TestJavaScriptDialogPresenter reusable.

ios/web/public/test/fakes/test_java_script_dialog_presenter.mm

+// 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.
+
+#import "ios/web/public/test/fakes/test_java_script_dialog_presenter.h"
+
+namespace web {
+
+TestJavaScriptDialog::TestJavaScriptDialog() = default;
+
+TestJavaScriptDialog::TestJavaScriptDialog(const TestJavaScriptDialog&) =
+    default;
+
+TestJavaScriptDialog::~TestJavaScriptDialog() = default;
+
+TestJavaScriptDialogPresenter::TestJavaScriptDialogPresenter() = default;
+
+TestJavaScriptDialogPresenter::~TestJavaScriptDialogPresenter() = default;
+
+void TestJavaScriptDialogPresenter::RunJavaScriptDialog(
+    WebState* web_state,
+    const GURL& origin_url,
+    JavaScriptDialogType java_script_dialog_type,
+    NSString* message_text,
+    NSString* default_prompt_text,
+    const DialogClosedCallback& callback) {
+  TestJavaScriptDialog dialog;
+  dialog.web_state = web_state;
+  dialog.origin_url = origin_url;
+  dialog.java_script_dialog_type = java_script_dialog_type;
+  dialog.message_text.reset(message_text);
+  dialog.default_prompt_text.reset(default_prompt_text);
+
+  requested_dialogs_.push_back(dialog);
+
+  callback.Run(callback_success_argument_, callback_user_input_argument_.get());
+}
+
+void TestJavaScriptDialogPresenter::CancelDialogs(WebState* web_state) {
+  cancel_dialogs_called_ = true;
+}
+
+}  // namespace web