Add request throttler to thumbnail fetching for articles on mobile NTP

components/ntp_snippets/ntp_snippets_fetcher.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 "components/ntp_snippets/ntp_snippets_fetcher.h"
 
 #include <stdlib.h>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 194 matching lines @@
 
 void NTPSnippetsFetcher::SetCallback(
     const SnippetsAvailableCallback& callback) {
   snippets_available_callback_ = callback;
 }
 
 void NTPSnippetsFetcher::FetchSnippetsFromHosts(
     const std::set<std::string>& hosts,
     const std::string& language_code,
     int count,
-    bool force_request) {
-  if (!request_throttler_.DemandQuotaForRequest(force_request))
+    bool interactive_request) {
+  if (!request_throttler_.DemandQuotaForRequest(interactive_request))
     return;
 
   hosts_ = hosts;
   fetch_start_time_ = tick_clock_->NowTicks();
 
   if (UsesHostRestrictions() && hosts_.empty()) {
     FetchFinished(OptionalSnippets(), FetchResult::EMPTY_HOSTS,
                   /*extra_message=*/std::string());
     return;
   }
@@ skipping 337 matching lines @@
                       tick_clock_->NowTicks() - fetch_start_time_);
   UMA_HISTOGRAM_ENUMERATION("NewTabPage.Snippets.FetchResult",
                             static_cast<int>(result),
                             static_cast<int>(FetchResult::RESULT_MAX));
 
   if (!snippets_available_callback_.is_null())
     snippets_available_callback_.Run(std::move(snippets));
 }
 
 }  // namespace ntp_snippets