Fix ntp-tiles-internals crash in incognito mode

ios/chrome/browser/ui/webui/ntp_tiles_internals_ui.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 "ios/chrome/browser/ui/webui/ntp_tiles_internals_ui.h"
 
 #include "base/memory/ptr_util.h"
 #include "components/grit/components_resources.h"
 #include "components/ntp_tiles/field_trial.h"
 #include "components/ntp_tiles/most_visited_sites.h"
@@ skipping 16 matching lines @@
     : public web::WebUIIOSMessageHandler,
       public ntp_tiles::NTPTilesInternalsMessageHandlerClient {
  public:
   IOSNTPTilesInternalsMessageHandlerBridge() {}
 
  private:
   // web::WebUIIOSMessageHandler:
   void RegisterMessages() override;
 
   // ntp_tiles::NTPTilesInternalsMessageHandlerClient
+  bool SupportsNTPTiles() override;
   bool DoesSourceExist(ntp_tiles::NTPTileSource source) override;
   std::unique_ptr<ntp_tiles::MostVisitedSites> MakeMostVisitedSites() override;
   std::unique_ptr<ntp_tiles::PopularSites> MakePopularSites() override;
   PrefService* GetPrefs() override;
   void RegisterMessageCallback(
       const std::string& message,
       const base::Callback<void(const base::ListValue*)>& callback) override;
   void CallJavascriptFunctionVector(
       const std::string& name,
       const std::vector<const base::Value*>& values) override;
 
   ntp_tiles::NTPTilesInternalsMessageHandler handler_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSNTPTilesInternalsMessageHandlerBridge);
 };
 
 void IOSNTPTilesInternalsMessageHandlerBridge::RegisterMessages() {
   handler_.RegisterMessages(this);
 }
 
+bool IOSNTPTilesInternalsMessageHandlerBridge::SupportsNTPTiles() {
+  auto* state = ios::ChromeBrowserState::FromWebUIIOS(web_ui());
+  return !state->HasOffTheRecordChromeBrowserState();
+}
+
 bool IOSNTPTilesInternalsMessageHandlerBridge::DoesSourceExist(
     ntp_tiles::NTPTileSource source) {
   switch (source) {
     case ntp_tiles::NTPTileSource::TOP_SITES:
     case ntp_tiles::NTPTileSource::SUGGESTIONS_SERVICE:
     case ntp_tiles::NTPTileSource::POPULAR:
       return true;
     case ntp_tiles::NTPTileSource::WHITELIST:
       return false;
   }
@@ skipping 44 matching lines @@
 
 NTPTilesInternalsUI::NTPTilesInternalsUI(web::WebUIIOS* web_ui)
     : web::WebUIIOSController(web_ui) {
   web::WebUIIOSDataSource::Add(ios::ChromeBrowserState::FromWebUIIOS(web_ui),
                                CreateNTPTilesInternalsHTMLSource());
   web_ui->AddMessageHandler(
       base::MakeUnique<IOSNTPTilesInternalsMessageHandlerBridge>());
 }
 
 NTPTilesInternalsUI::~NTPTilesInternalsUI() {}