Mock the LinkDoctor for tests. Should greatly decrease ErrorPage test flakiness.

chrome/browser/net/url_request_mock_link_doctor_job.cc

+// Copyright (c) 2009 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/net/url_request_mock_link_doctor_job.h"
+
+#include "base/path_service.h"
+#include "chrome/browser/google_util.h"
+#include "chrome/common/chrome_paths.h"
+#include "googleurl/src/gurl.h"
+#include "net/url_request/url_request_filter.h"
+
+namespace {
+
+FilePath GetMockFilePath() {
+  FilePath test_dir;
+  bool success = PathService::Get(chrome::DIR_TEST_DATA, &test_dir);
+  DCHECK(success);
+  return test_dir.AppendASCII("mock-link-doctor.html");
+}
+
+}  // namespace
+
+/* static */
+URLRequestJob* URLRequestMockLinkDoctorJob::Factory(URLRequest* request,
+                                                    const std::string& scheme) {
+  return new URLRequestMockLinkDoctorJob(request);
+}
+
+/* static */
+void URLRequestMockLinkDoctorJob::AddUrlHandler() {
+  URLRequestFilter* filter = URLRequestFilter::GetInstance();
+  filter->AddHostnameHandler("http",
+                             GURL(google_util::kLinkDoctorBaseURL).host(),
+                             URLRequestMockLinkDoctorJob::Factory);
+}
+
+URLRequestMockLinkDoctorJob::URLRequestMockLinkDoctorJob(URLRequest* request)
+    : URLRequestMockHTTPJob(request, GetMockFilePath()) {
+}