Eliminate NOTIFICATION_HISTORY_LOADED notification

chrome/browser/safe_browsing/incident_reporting/last_download_finder.cc

 // Copyright 2014 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/safe_browsing/incident_reporting/last_download_finder.h"
 
 #include <algorithm>
 #include <functional>
 #include <utility>
 
@@ skipping 106 matching lines @@
 
 LastDownloadFinder::LastDownloadFinder(const std::vector<Profile*>& profiles,
                                        const LastDownloadCallback& callback)
     : callback_(callback), weak_ptr_factory_(this) {
   // Observe profile lifecycle events so that the finder can begin or abandon
   // the search in profiles while it is running.
   notification_registrar_.Add(this,
                               chrome::NOTIFICATION_PROFILE_ADDED,
                               content::NotificationService::AllSources());
   notification_registrar_.Add(this,
-                              chrome::NOTIFICATION_HISTORY_LOADED,
-                              content::NotificationService::AllSources());
-  notification_registrar_.Add(this,
                               chrome::NOTIFICATION_PROFILE_DESTROYED,
                               content::NotificationService::AllSources());
 
   // Begin the seach for all given profiles.
   std::for_each(
       profiles.begin(),
       profiles.end(),
       std::bind1st(std::mem_fun(&LastDownloadFinder::SearchInProfile), this));
 }
 
@@ skipping 18 matching lines @@
   // No history service is returned for profiles that do not save history.
   if (!history_service)
     return;
 
   profiles_.push_back(profile);
   if (history_service->BackendLoaded()) {
     history_service->QueryDownloads(
         base::Bind(&LastDownloadFinder::OnDownloadQuery,
                    weak_ptr_factory_.GetWeakPtr(),
                    profile));
-  }  // else wait until history is loaded.
+  } else {
+    // else wait until history is loaded.
+    history_service->AddHistoryServiceObserver(this);
+  }
 }
 
 void LastDownloadFinder::OnProfileHistoryLoaded(
     Profile* profile,
     HistoryService* history_service) {
   if (std::find(profiles_.begin(), profiles_.end(), profile) !=
       profiles_.end()) {
     history_service->QueryDownloads(
         base::Bind(&LastDownloadFinder::OnDownloadQuery,
                    weak_ptr_factory_.GetWeakPtr(),
@@ skipping 56 matching lines @@
   }
 }
 
 void LastDownloadFinder::Observe(int type,
                                  const content::NotificationSource& source,
                                  const content::NotificationDetails& details) {
   switch (type) {
     case chrome::NOTIFICATION_PROFILE_ADDED:
       SearchInProfile(content::Source<Profile>(source).ptr());
       break;
-    case chrome::NOTIFICATION_HISTORY_LOADED:
-      OnProfileHistoryLoaded(content::Source<Profile>(source).ptr(),
-                             content::Details<HistoryService>(details).ptr());
-      break;
     case chrome::NOTIFICATION_PROFILE_DESTROYED:
       AbandonSearchInProfile(content::Source<Profile>(source).ptr());
       break;
     default:
       break;
   }
 }
 
+void LastDownloadFinder::HistoryServiceLoaded(HistoryService* history_service) {
+  OnProfileHistoryLoaded(history_service->profile(), history_service);
+  history_service->RemoveHistoryServiceObserver(this);
+}
+
 }  // namespace safe_browsing