Eliminate NOTIFICATION_HISTORY_LOADED notification

chrome/browser/predictors/autocomplete_action_predictor.cc

 // Copyright (c) 2012 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/predictors/autocomplete_action_predictor.h"
 
 #include <math.h>
 
 #include <vector>
 
@@ skipping 79 matching lines @@
 
     // Observe all main frame loads so we can wait for the first to complete
     // before accessing DB and IO threads to build the local cache.
     notification_registrar_.Add(this,
                                 content::NOTIFICATION_LOAD_COMPLETED_MAIN_FRAME,
                                 content::NotificationService::AllSources());
   }
 }
 
 AutocompleteActionPredictor::~AutocompleteActionPredictor() {
+  HistoryService* history_service =

[sdefresne, 2014/09/23 08:45:09]

AutocompleteActionPredictor is a KeyedService. Shouldn't the unregistration
happens in the Shutdown method instead?

[sdefresne, 2014/10/20 13:15:42]

Please move the unregistration into AutocompleteActionPredictor::Shutdown().

[nshaik, 2014/10/29 08:43:39]

Done.

+      HistoryServiceFactory::GetForProfile(profile_, Profile::EXPLICIT_ACCESS);
+  if (history_service)

[sdefresne, 2014/10/20 13:15:42]

Use ScopedObserver<>.

+    history_service->RemoveHistoryServiceObserver(this);
   if (main_profile_predictor_)
     main_profile_predictor_->incognito_predictor_ = NULL;
   else if (incognito_predictor_)
     incognito_predictor_->main_profile_predictor_ = NULL;
   if (prerender_handle_.get())
     prerender_handle_->OnCancel();
 }
 
 void AutocompleteActionPredictor::RegisterTransitionalMatches(
     const base::string16& user_text,
@@ skipping 140 matching lines @@
 
     case chrome::NOTIFICATION_OMNIBOX_OPENED_URL: {
       DCHECK(initialized_);
 
       // TODO(dominich): This doesn't need to be synchronous. Investigate
       // posting it as a task to be run later.
       OnOmniboxOpenedUrl(*content::Details<OmniboxLog>(details).ptr());
       break;
     }
 
-    case chrome::NOTIFICATION_HISTORY_LOADED: {
-      TryDeleteOldEntries(content::Details<HistoryService>(details).ptr());
-
-      notification_registrar_.Remove(this,
-                                     chrome::NOTIFICATION_HISTORY_LOADED,
-                                     content::Source<Profile>(profile_));
-      break;
-    }
-
     default:
       NOTREACHED() << "Unexpected notification observed.";
       break;
   }
 }
 
 void AutocompleteActionPredictor::CreateLocalCachesFromDatabase() {
   // Create local caches using the database as loaded. We will garbage collect
   // rows from the caches and the database once the history service is
   // available.
@@ skipping 195 matching lines @@
     db_cache_[key] = value;
     db_id_cache_[key] = it->id;
   }
 
   // If the history service is ready, delete any old or invalid entries.
   HistoryService* history_service =
       HistoryServiceFactory::GetForProfile(profile_, Profile::EXPLICIT_ACCESS);
   if (!TryDeleteOldEntries(history_service)) {
     // Wait for the notification that the history service is ready and the URL
     // DB is loaded.
-    notification_registrar_.Add(this, chrome::NOTIFICATION_HISTORY_LOADED,
-                                content::Source<Profile>(profile_));
+    history_service->AddHistoryServiceObserver(this);
   }
 }
 
 bool AutocompleteActionPredictor::TryDeleteOldEntries(HistoryService* service) {
   CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   DCHECK(!profile_->IsOffTheRecord());
   DCHECK(!initialized_);
 
   if (!service)
     return false;
@@ skipping 106 matching lines @@
   const double number_of_hits = static_cast<double>(value.number_of_hits);
   return number_of_hits / (number_of_hits + value.number_of_misses);
 }
 
 AutocompleteActionPredictor::TransitionalMatch::TransitionalMatch() {
 }
 
 AutocompleteActionPredictor::TransitionalMatch::~TransitionalMatch() {
 }
 
+void AutocompleteActionPredictor::HistoryServiceLoaded(
+    HistoryService* history_service) {
+  TryDeleteOldEntries(history_service);
+  history_service->RemoveHistoryServiceObserver(this);
+}
+
 }  // namespace predictors