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

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

 // Copyright (c) 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.
 
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/extensions/api/dial/device_description_fetcher.h"
 #include "chrome/browser/extensions/api/dial/dial_device_data.h"
 #include "chrome/browser/profiles/profile.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 10 matching lines @@
 // DIAL devices are unlikely to expose uPnP functions other than DIAL, so 256kb
 // should be more than sufficient.
 constexpr int kMaxDescriptionSizeBytes = 262144;
 
 namespace extensions {
 namespace api {
 namespace dial {
 
 DeviceDescriptionFetcher::DeviceDescriptionFetcher(
     const GURL& device_description_url,
-    Profile* profile,
+    net::URLRequestContextGetter* request_context,
+    BrowserThread::ID thread_id,

[imcheng, 2017/03/06 20:56:30]

thread_id can be removed now.

[zhaobin, 2017/03/07 00:13:18]

Done.

     base::OnceCallback<void(const DialDeviceDescriptionData&)> success_cb,
     base::OnceCallback<void(const std::string&)> error_cb)
     : device_description_url_(device_description_url),
-      profile_(profile),
+      request_context_(request_context),
       success_cb_(std::move(success_cb)),
       error_cb_(std::move(error_cb)) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  DCHECK(profile_);
+  DCHECK(thread_checker_.CalledOnValidThread());

[imcheng, 2017/03/06 20:56:30]

this DCHECK is not necessary since it's just been created.

[zhaobin, 2017/03/07 00:13:18]

Done.

+  DCHECK(request_context_);
   DCHECK(device_description_url_.is_valid());
 }
 
 DeviceDescriptionFetcher::~DeviceDescriptionFetcher() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void DeviceDescriptionFetcher::Start() {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!fetcher_);
 
   // DIAL returns device descriptions via GET request.
   fetcher_ =
       net::URLFetcher::Create(kURLFetcherIDForTest, device_description_url_,
                               net::URLFetcher::GET, this);
 
   // net::LOAD_BYPASS_PROXY: Proxies almost certainly hurt more cases than they
   //     help.
   // net::LOAD_DISABLE_CACHE: The request should not touch the cache.
   // net::LOAD_DO_NOT_{SAVE,SEND}_COOKIES: The request should not touch cookies.
   // net::LOAD_DO_NOT_SEND_AUTH_DATA: The request should not send auth data.
   fetcher_->SetLoadFlags(net::LOAD_BYPASS_PROXY | net::LOAD_DISABLE_CACHE |
                          net::LOAD_DO_NOT_SAVE_COOKIES |
                          net::LOAD_DO_NOT_SEND_COOKIES |
                          net::LOAD_DO_NOT_SEND_AUTH_DATA);
 
   // Section 5.4 of the DIAL spec prohibits redirects.
   fetcher_->SetStopOnRedirect(true);
 
   // Allow the fetcher to retry on 5XX responses and ERR_NETWORK_CHANGED.
   fetcher_->SetMaxRetriesOn5xx(kMaxRetries);
   fetcher_->SetAutomaticallyRetryOnNetworkChanges(kMaxRetries);
 
-  fetcher_->SetRequestContext(profile_->GetRequestContext());
+  fetcher_->SetRequestContext(request_context_);
   fetcher_->Start();
 }
 
 void DeviceDescriptionFetcher::OnURLFetchComplete(
     const net::URLFetcher* source) {
   DCHECK_EQ(fetcher_.get(), source);
 
   if (source->GetResponseCode() != net::HTTP_OK) {
     ReportError(
         base::StringPrintf("HTTP %d: Unable to fetch device description",
@@ skipping 57 matching lines @@
     int64_t current,
     int64_t total) {}
 
 void DeviceDescriptionFetcher::ReportError(const std::string& message) {
   std::move(error_cb_).Run(message);
 }
 
 }  // namespace dial
 }  // namespace api
 }  // namespace extensions