[Dial] Refactor DialRegistry and DeviceDescriptionFetcher so they can be used by MediaSinkService

chrome/browser/extensions/api/dial/device_description_fetcher_unittest.cc

 // Copyright (c) 2016 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 <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
@@ skipping 29 matching lines @@
                                  expected_description);
   }
 
   void ExpectError(const std::string& expected_message) {
     error_cb_ = base::BindOnce(&DeviceDescriptionFetcherTest::OnError,
                                base::Unretained(this), expected_message);
   }
 
   net::TestURLFetcher* StartRequest() {
     fetcher_ = base::MakeUnique<DeviceDescriptionFetcher>(
-        url_, &profile_, std::move(success_cb_), std::move(error_cb_));
+        url_, profile_.GetRequestContext(), std::move(success_cb_),
+        std::move(error_cb_));
     fetcher_->Start();
     return factory_.GetFetcherByID(
         DeviceDescriptionFetcher::kURLFetcherIDForTest);
   }
 
  protected:
   const content::TestBrowserThreadBundle thread_bundle_;
   TestingProfile profile_;
   const net::TestURLFetcherFactory factory_;
   const GURL url_;
@@ skipping 108 matching lines @@
       new net::HttpResponseHeaders("");
   headers->AddHeader("Application-URL: http://127.0.0.1/apps");
   test_fetcher->set_response_headers(headers);
   test_fetcher->SetResponseString(std::string(262145, 'd'));
   test_fetcher->delegate()->OnURLFetchComplete(test_fetcher);
 }
 
 }  // namespace dial
 }  // namespace api
 }  // namespace extensions