Remove |not_updated| from ExtensionDownloader::HandleManifestResults

Years ago there was a variable |not_updated| in

handle successfully/unsuccessfully downloaded extension manifests. Now
it is handled more elegant via ExtensionDownloader::DetermineUpdates
method, so we may remove it and replace its only usage with actual data.

ExtensionDownloader: :HandleManifestResults method, and it was used to
Change-Id: I188b588c061dd6595c2bb5d6030afe5200b28130
Reviewed-on: https://chromium-review.googlesource.com/c/1486271Reviewed-by: Vladislav Kuzkokov <vkuzkokov@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Oleg Davydov <burunduk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#635442}

extensions/browser/updater/extension_downloader.cc

@@ -653,14 +653,11 @@ void ExtensionDownloader::HandleManifestResults(
     std::unique_ptr<ManifestFetchData> fetch_data,
     std::unique_ptr<UpdateManifestResults> results,
     const base::Optional<std::string>& error) {
-  // Keep a list of extensions that will not be updated, so that the |delegate_|
-  // can be notified once we're done here.
-  std::set<std::string> not_updated(fetch_data->extension_ids());
 
   if (!results) {
     VLOG(2) << "parsing manifest failed (" << fetch_data->full_url() << ")";
     NotifyExtensionsDownloadFailed(
-        not_updated, fetch_data->request_ids(),
+        fetch_data->extension_ids(), fetch_data->request_ids(),
         ExtensionDownloaderDelegate::MANIFEST_INVALID);
     return;
   } else {
@@ -1077,8 +1074,8 @@ void ExtensionDownloader::OnExtensionLoadComplete(base::FilePath crx_path) {
 }
 
 void ExtensionDownloader::NotifyExtensionsDownloadFailed(
-    const std::set<std::string>& extension_ids,
-    const std::set<int>& request_ids,
+    std::set<std::string> extension_ids,
+    std::set<int> request_ids,
     ExtensionDownloaderDelegate::Error error) {
   for (auto it = extension_ids.cbegin(); it != extension_ids.cend(); ++it) {
     const ExtensionDownloaderDelegate::PingResult& ping = ping_results_[*it];

extensions/browser/updater/extension_downloader.h

@@ -284,9 +284,11 @@ class ExtensionDownloader {
   void OnExtensionLoadComplete(base::FilePath crx_path);
 
   // Invokes OnExtensionDownloadFailed() on the |delegate_| for each extension
-  // in the set, with |error| as the reason for failure.
-  void NotifyExtensionsDownloadFailed(const std::set<std::string>& id_set,
-                                      const std::set<int>& request_ids,
+  // in the set, with |error| as the reason for failure. Make a copy of
+  // arguments because there is no guarantee that callback won't indirectly
+  // change source of IDs.
+  void NotifyExtensionsDownloadFailed(std::set<std::string> id_set,
+                                      std::set<int> request_ids,
                                       ExtensionDownloaderDelegate::Error error);
 
   // Send a notification that an update was found for |id| that we'll