Add new NTP layout with snippet cards and hide it behind a flag

chrome/browser/android/ntp/ntp_snippets_bridge.cc

Index: chrome/browser/android/ntp/ntp_snippets_bridge.cc
diff --git a/chrome/browser/android/ntp/ntp_snippets_bridge.cc b/chrome/browser/android/ntp/ntp_snippets_bridge.cc
index 9af0c09db71460153911cffb102d6606dd62573f..f1114eddecc89bd808ccc0d4f25d37a1b0bb974d 100644
--- a/chrome/browser/android/ntp/ntp_snippets_bridge.cc
+++ b/chrome/browser/android/ntp/ntp_snippets_bridge.cc
@@ -18,6 +18,7 @@
 
 using base::android::JavaParamRef;
 using base::android::ToJavaArrayOfStrings;
+using base::android::ToJavaLongArray;
 using ntp_snippets::NTPSnippetsService;
 using ntp_snippets::NTPSnippetsServiceObserver;
 
@@ -59,11 +60,13 @@ void NTPSnippetsBridge::NTPSnippetsServiceLoaded(NTPSnippetsService* service) {
   std::vector<std::string> urls;
   std::vector<std::string> thumbnail_urls;
   std::vector<std::string> snippets;
+  std::vector<int64_t> timestamps;
   for (const ntp_snippets::NTPSnippet& snippet : *service) {
     titles.push_back(snippet.title());
     urls.push_back(snippet.url().spec());
     thumbnail_urls.push_back(snippet.salient_image_url().spec());
     snippets.push_back(snippet.snippet());
+    timestamps.push_back(snippet.publish_date().ToJavaTime());
   }
 
   JNIEnv* env = base::android::AttachCurrentThread();
@@ -71,7 +74,8 @@ void NTPSnippetsBridge::NTPSnippetsServiceLoaded(NTPSnippetsService* service) {
       env, observer_.obj(), ToJavaArrayOfStrings(env, titles).obj(),
       ToJavaArrayOfStrings(env, urls).obj(),
       ToJavaArrayOfStrings(env, thumbnail_urls).obj(),
-      ToJavaArrayOfStrings(env, snippets).obj());
+      ToJavaArrayOfStrings(env, snippets).obj(),
+      ToJavaLongArray(env, timestamps).obj());
 }
 
 void NTPSnippetsBridge::NTPSnippetsServiceShutdown(