[NTP Snippets] Refactor home-grown container API

chrome/browser/android/ntp/ntp_snippets_bridge.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/android/ntp/ntp_snippets_bridge.h"
 
 #include <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
@@ skipping 119 matching lines @@
   // URL for the article. This will also be used to find the favicon for the
   // article.
   std::vector<std::string> urls;
   // URL for the AMP version of the article if it exists. This will be used as
   // the URL to direct the user to on tap.
   std::vector<std::string> amp_urls;
   std::vector<std::string> thumbnail_urls;
   std::vector<std::string> snippets;
   std::vector<int64_t> timestamps;
   std::vector<std::string> publishers;
-  for (const ntp_snippets::NTPSnippet& snippet : *ntp_snippets_service_) {
+  for (const std::unique_ptr<ntp_snippets::NTPSnippet>& snippet :
+       ntp_snippets_service_->snippets()) {
     // The url from source_info is a url for a site that is one of the
     // HOST_RESTRICT parameters, so this is preferred.
-    urls.push_back(snippet.best_source().url.spec());
-    amp_urls.push_back(snippet.best_source().amp_url.spec());
-    titles.push_back(snippet.title());
-    thumbnail_urls.push_back(snippet.salient_image_url().spec());
-    snippets.push_back(snippet.snippet());
-    timestamps.push_back(snippet.publish_date().ToJavaTime());
-    publishers.push_back(snippet.best_source().publisher_name);
+    urls.push_back(snippet->best_source().url.spec());
+    amp_urls.push_back(snippet->best_source().amp_url.spec());
+    titles.push_back(snippet->title());
+    thumbnail_urls.push_back(snippet->salient_image_url().spec());
+    snippets.push_back(snippet->snippet());
+    timestamps.push_back(snippet->publish_date().ToJavaTime());
+    publishers.push_back(snippet->best_source().publisher_name);
   }
 
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_SnippetsBridge_onSnippetsAvailable(
       env, observer_.obj(), ToJavaArrayOfStrings(env, titles).obj(),
       ToJavaArrayOfStrings(env, urls).obj(),
       ToJavaArrayOfStrings(env, amp_urls).obj(),
       ToJavaArrayOfStrings(env, thumbnail_urls).obj(),
       ToJavaArrayOfStrings(env, snippets).obj(),
       ToJavaLongArray(env, timestamps).obj(),
@@ skipping 15 matching lines @@
     j_bitmap = gfx::ConvertToJavaBitmap(bitmap);
 
   Java_FetchSnippetImageCallback_onSnippetImageAvailable(env, callback.obj(),
                                                          j_bitmap.obj());
 }
 
 // static
 bool NTPSnippetsBridge::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }