Componentize component_updater: Replace content::BrowserThread usage with task runners

chrome/browser/component_updater/url_fetcher_downloader.cc

 // Copyright 2013 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/component_updater/url_fetcher_downloader.h"
 
 #include "base/logging.h"
+#include "base/sequenced_task_runner.h"
 #include "chrome/browser/component_updater/component_updater_utils.h"
-#include "content/public/browser/browser_thread.h"
 #include "net/base/load_flags.h"
 #include "net/url_request/url_fetcher.h"
 #include "url/gurl.h"
 
-using content::BrowserThread;
-
 namespace component_updater {
 
 UrlFetcherDownloader::UrlFetcherDownloader(
     scoped_ptr<CrxDownloader> successor,
     net::URLRequestContextGetter* context_getter,
     scoped_refptr<base::SequencedTaskRunner> task_runner)
     : CrxDownloader(successor.Pass()),
       context_getter_(context_getter),
       task_runner_(task_runner),
       downloaded_bytes_(-1),
       total_bytes_(-1) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
 UrlFetcherDownloader::~UrlFetcherDownloader() {
+  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void UrlFetcherDownloader::DoStartDownload(const GURL& url) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   url_fetcher_.reset(
       net::URLFetcher::Create(0, url, net::URLFetcher::GET, this));
   url_fetcher_->SetRequestContext(context_getter_);
   url_fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                              net::LOAD_DO_NOT_SAVE_COOKIES |
                              net::LOAD_DISABLE_CACHE);
   url_fetcher_->SetAutomaticallyRetryOn5xx(false);
   url_fetcher_->SaveResponseToTemporaryFile(task_runner_);
 
   VLOG(1) << "Starting background download: " << url.spec();
   url_fetcher_->Start();
 
   download_start_time_ = base::Time::Now();
 
   downloaded_bytes_ = -1;
   total_bytes_ = -1;
 }
 
 void UrlFetcherDownloader::OnURLFetchComplete(const net::URLFetcher* source) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   const base::Time download_end_time(base::Time::Now());
   const base::TimeDelta download_time =
       download_end_time >= download_start_time_
           ? download_end_time - download_start_time_
           : base::TimeDelta();
 
   // Consider a 5xx response from the server as an indication to terminate
   // the request and avoid overloading the server in this case.
   // is not accepting requests for the moment.
@@ skipping 21 matching lines @@
   VLOG(1) << "Downloaded " << downloaded_bytes_ << " bytes in "
           << download_time.InMilliseconds() << "ms from "
           << source->GetURL().spec() << " to " << local_path_.value();
   CrxDownloader::OnDownloadComplete(is_handled, result, download_metrics);
 }
 
 void UrlFetcherDownloader::OnURLFetchDownloadProgress(
     const net::URLFetcher* source,
     int64 current,
     int64 total) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK(thread_checker_.CalledOnValidThread());
 
   downloaded_bytes_ = current;
   total_bytes_ = total;
 
   Result result;
   result.downloaded_bytes = downloaded_bytes_;
   result.total_bytes = total_bytes_;
 
   OnDownloadProgress(result);
 }
 
 }  // namespace component_updater