Enable NTPTilesInInstantService by default

chrome/browser/search/instant_service.cc

 // Copyright 2013 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/search/instant_service.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/feature_list.h"
@@ skipping 42 matching lines @@
 #if !defined(OS_ANDROID)
 #include "chrome/browser/search/local_ntp_source.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #endif
 
 namespace {
 
 const base::Feature kNtpTilesFeature{"NTPTilesInInstantService",
-                                     base::FEATURE_DISABLED_BY_DEFAULT};
+                                     base::FEATURE_ENABLED_BY_DEFAULT};
 
 }  // namespace
 
 InstantService::InstantService(Profile* profile)
     : profile_(profile),
       template_url_service_(TemplateURLServiceFactory::GetForProfile(profile_)),
       weak_ptr_factory_(this) {
   // The initialization below depends on a typical set of browser threads. Skip
   // it if we are running in a unit test without the full suite.
   if (!content::BrowserThread::CurrentlyOn(content::BrowserThread::UI))
@@ skipping 431 matching lines @@
 void InstantService::ResetInstantSearchPrerendererIfNecessary() {
   if (!search::IsInstantExtendedAPIEnabled())
     return;
 
   GURL url(search::GetSearchResultPrefetchBaseURL(profile_));
   if (!instant_prerenderer_ || instant_prerenderer_->prerender_url() != url) {
     instant_prerenderer_.reset(
         url.is_valid() ? new InstantSearchPrerenderer(profile_, url) : nullptr);
   }
 }