ntp_tiles: Migrate to multi-observer model

components/ntp_tiles/webui/ntp_tiles_internals_message_handler.cc

 // Copyright 2016 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 "components/ntp_tiles/webui/ntp_tiles_internals_message_handler.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
 #include "components/ntp_tiles/most_visited_sites.h"
 #include "components/ntp_tiles/pref_names.h"
 #include "components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h"
 #include "components/prefs/pref_service.h"
 #include "components/url_formatter/url_fixer.h"
 #include "url/gurl.h"
 
 namespace ntp_tiles {
 
 NTPTilesInternalsMessageHandlerClient::NTPTilesInternalsMessageHandlerClient() =
     default;
 NTPTilesInternalsMessageHandlerClient::
     ~NTPTilesInternalsMessageHandlerClient() = default;
 
 NTPTilesInternalsMessageHandler::NTPTilesInternalsMessageHandler()
-    : client_(nullptr), site_count_(8) {}
+    : client_(nullptr) {}
 
 NTPTilesInternalsMessageHandler::~NTPTilesInternalsMessageHandler() = default;
 
 void NTPTilesInternalsMessageHandler::RegisterMessages(
     NTPTilesInternalsMessageHandlerClient* client) {
   client_ = client;
 
   client_->RegisterMessageCallback(
       "registerForEvents",
       base::Bind(&NTPTilesInternalsMessageHandler::HandleRegisterForEvents,
                  base::Unretained(this)));
 
   client_->RegisterMessageCallback(
       "update", base::Bind(&NTPTilesInternalsMessageHandler::HandleUpdate,
                            base::Unretained(this)));
 }
 
 void NTPTilesInternalsMessageHandler::HandleRegisterForEvents(
     const base::ListValue* args) {
   DCHECK(args->empty());
 
   SendSourceInfo();
 
   most_visited_sites_ = client_->MakeMostVisitedSites();
-  most_visited_sites_->SetMostVisitedURLsObserver(this, site_count_);
+  most_visited_sites_->AddObserver(this);
+  most_visited_sites_->Refresh();
 }
 
 void NTPTilesInternalsMessageHandler::HandleUpdate(
     const base::ListValue* args) {
   const base::DictionaryValue* dict = nullptr;
   DCHECK_EQ(1u, args->GetSize());
   args->GetDictionary(0, &dict);
   DCHECK(dict);
 
   PrefService* prefs = client_->GetPrefs();
@@ skipping 22 matching lines @@
       prefs->ClearPref(ntp_tiles::prefs::kPopularSitesOverrideVersion);
     } else {
       prefs->SetString(ntp_tiles::prefs::kPopularSitesOverrideVersion, version);
     }
   }
 
   // Recreate to pick up new values.
   // TODO(sfiera): refresh MostVisitedSites without re-creating it, as soon as
   // that will pick up changes to the Popular Sites overrides.
   most_visited_sites_ = client_->MakeMostVisitedSites();
-  most_visited_sites_->SetMostVisitedURLsObserver(this, site_count_);
+  most_visited_sites_->AddObserver(this);
+  most_visited_sites_->Refresh();
   SendSourceInfo();
 }
 
 void NTPTilesInternalsMessageHandler::SendSourceInfo() {
   PrefService* prefs = client_->GetPrefs();
   base::DictionaryValue value;
 
   value.SetBoolean("topSites",
                    client_->DoesSourceExist(NTPTileSource::TOP_SITES));
   value.SetBoolean(
@@ skipping 45 matching lines @@
 
 void NTPTilesInternalsMessageHandler::OnMostVisitedURLsAvailable(
     const NTPTilesVector& tiles) {
   SendTiles(tiles);
 }
 
 void NTPTilesInternalsMessageHandler::OnIconMadeAvailable(
     const GURL& site_url) {}
 
 }  // namespace ntp_tiles