Clear browsing data from ContentSuggestionService only if exists.

chrome/browser/ntp_snippets/content_suggestions_service_factory.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 "chrome/browser/ntp_snippets/content_suggestions_service_factory.h"
 
 #include "base/feature_list.h"
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/singleton.h"
@@ skipping 166 matching lines @@
   return base::Singleton<ContentSuggestionsServiceFactory>::get();
 }
 
 // static
 ContentSuggestionsService* ContentSuggestionsServiceFactory::GetForProfile(
     Profile* profile) {
   return static_cast<ContentSuggestionsService*>(
       GetInstance()->GetServiceForBrowserContext(profile, true));
 }
 
+// static
+ContentSuggestionsService*
+ContentSuggestionsServiceFactory::GetForProfileIfExists(Profile* profile) {
+  return static_cast<ContentSuggestionsService*>(
+      GetInstance()->GetServiceForBrowserContext(profile, false));
+}
+
 ContentSuggestionsServiceFactory::ContentSuggestionsServiceFactory()
     : BrowserContextKeyedServiceFactory(
           "ContentSuggestionsService",
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(BookmarkModelFactory::GetInstance());
   DependsOn(HistoryServiceFactory::GetInstance());
 #if defined(OS_ANDROID)
   DependsOn(OfflinePageModelFactory::GetInstance());
 #endif  // OS_ANDROID
   DependsOn(ProfileOAuth2TokenServiceFactory::GetInstance());
@@ skipping 65 matching lines @@
   }
 #endif  // OS_ANDROID
 
   if (base::FeatureList::IsEnabled(ntp_snippets::kArticleSuggestionsFeature)) {
     RegisterArticleProvider(signin_manager, token_service, suggestions_service,
                             service, category_factory, pref_service, profile);
   }
 
   return service;
 }