[NTP::PhysicalWeb] Enable by default and depend on physical web flag.

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 <utility>
 
 #include "base/feature_list.h"
 #include "base/files/file_path.h"
@@ skipping 122 matching lines @@
 
 void RegisterBookmarkProvider(BookmarkModel* bookmark_model,
                               ContentSuggestionsService* service,
                               PrefService* pref_service) {
   auto provider = base::MakeUnique<BookmarkSuggestionsProvider>(
       service, bookmark_model, pref_service);
   service->RegisterProvider(std::move(provider));
 }
 
 #if defined(OS_ANDROID)
+
+bool IsPhysicalWebPageProviderEnabled() {
+  return base::FeatureList::IsEnabled(
+             ntp_snippets::kPhysicalWebPageSuggestionsFeature) &&
+         base::FeatureList::IsEnabled(chrome::android::kPhysicalWebFeature);
+}
+
 void RegisterPhysicalWebPageProvider(
     ContentSuggestionsService* service,
     PhysicalWebDataSource* physical_web_data_source,
     PrefService* pref_service) {
   auto provider = base::MakeUnique<PhysicalWebPageSuggestionsProvider>(
       service, physical_web_data_source, pref_service);
   service->RegisterProvider(std::move(provider));
 }
 #endif  // OS_ANDROID
 
@@ skipping 157 matching lines @@
   }
 #endif  // OS_ANDROID
 
   // |bookmark_model| can be null in tests.
   if (base::FeatureList::IsEnabled(ntp_snippets::kBookmarkSuggestionsFeature) &&
       bookmark_model) {
     RegisterBookmarkProvider(bookmark_model, service, pref_service);
   }
 
 #if defined(OS_ANDROID)
-  if (base::FeatureList::IsEnabled(
-          ntp_snippets::kPhysicalWebPageSuggestionsFeature)) {
+  if (IsPhysicalWebPageProviderEnabled()) {
     RegisterPhysicalWebPageProvider(service, physical_web_data_source,
                                     pref_service);
   }
 #endif  // OS_ANDROID
 
   if (base::FeatureList::IsEnabled(ntp_snippets::kArticleSuggestionsFeature)) {
     RegisterArticleProvider(signin_manager, token_service, service,
                             language_model, pref_service, profile);
   }
 
   if (base::FeatureList::IsEnabled(
           ntp_snippets::kForeignSessionsSuggestionsFeature)) {
     RegisterForeignSessionsProvider(sync_service, service, pref_service);
   }
 
   return service;
 }