Added support for multiple urls in the component updater.

chrome/browser/component_updater/crx_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/crx_downloader.h"
 #include "chrome/browser/component_updater/url_fetcher_downloader.h"
 #include "content/public/browser/browser_thread.h"
 
 #if defined(OS_WIN)
 #include "chrome/browser/component_updater/background_downloader_win.h"
@@ skipping 56 matching lines @@
   if (!successor_)
     return download_metrics_;
 
   std::vector<DownloadMetrics> retval(successor_->download_metrics());
   retval.insert(retval.begin(),
                 download_metrics_.begin(),
                 download_metrics_.end());
   return retval;
 }
 
-bool CrxDownloader::StartDownloadFromUrl(const GURL& url) {
+void CrxDownloader::StartDownloadFromUrl(const GURL& url) {
   std::vector<GURL> urls;
   urls.push_back(url);
-  return StartDownload(urls);
+  StartDownload(urls);
 }
 
-bool CrxDownloader::StartDownload(const std::vector<GURL>& urls) {
+void CrxDownloader::StartDownload(const std::vector<GURL>& urls) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
-  if (urls.empty())
-    return false;
+  if (urls.empty()) {
+    // Make a result and complete the download with a generic error for now.
+    Result result;
+    result.error = -1;
+    download_callback_.Run(result);
+    return;
+  }
 
   // If the urls are mutated while this downloader is active, then the
   // behavior is undefined in the sense that the outcome of the download could
   // be inconsistent for the list of urls. At any rate, the |current_url_| is
   // reset at this point, and the iterator will be valid in all conditions.
   urls_ = urls;
   current_url_ = urls_.begin();
 
   DoStartDownload(*current_url_);
-  return true;
 }
 
 void CrxDownloader::OnDownloadComplete(
     bool is_handled,
     const Result& result,
     const DownloadMetrics& download_metrics) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   download_metrics_.push_back(download_metrics);
 
@@ skipping 13 matching lines @@
     // Try downloading from another url from the list.
     if (current_url_ != urls_.end()) {
       DoStartDownload(*current_url_);
       return;
     }
 
     // If there is another downloader that can accept this request, then hand
     // the request over to it so that the successor can try the pruned list
     // of urls. Otherwise, the request ends here since the current downloader
     // has tried all urls and it can't fall back on any other downloader.
-    if (successor_ && successor_->StartDownload(urls_))
+    if (successor_ && !urls_.empty()) {
+      successor_->StartDownload(urls_);
       return;
+    }
   }
 
   download_callback_.Run(result);
 }
 
 }  // namespace component_updater