Add data usage tracking for NTP tiles

components/ntp_tiles/popular_sites.cc

 // Copyright 2015 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_tiles/popular_sites.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/files/important_file_writer.h"
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/path_service.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner_util.h"
 #include "base/time/time.h"
 #include "base/values.h"
+#include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/ntp_tiles/constants.h"
 #include "components/ntp_tiles/pref_names.h"
 #include "components/ntp_tiles/switches.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
 #include "components/search_engines/search_engine_type.h"
 #include "components/search_engines/template_url_service.h"
 #include "components/variations/service/variations_service.h"
 #include "components/variations/variations_associated_data.h"
@@ skipping 239 matching lines @@
       OnJsonParseFailed("previously-fetched JSON was no longer parseable");
     }
   } else {
     // File didn't exist, or couldn't be read for some other reason.
     FetchPopularSites();
   }
 }
 
 void PopularSites::FetchPopularSites() {
   fetcher_ = URLFetcher::Create(pending_url_, URLFetcher::GET, this);
+  data_use_measurement::DataUseUserData::AttachToFetcher(
+      fetcher_.get(), data_use_measurement::DataUseUserData::NTP_SNIPPETS);

[sfiera, 2016/08/25 05:39:46]

This doesn't seem like the right enum value. NTP_SNIPPETS is for
components/ntp_snippets, which has a different data usage pattern from here
(steady-state, vs. only new-ish users here).

Popular sites also downloads site icons, so a TODO to count that usage too would
be good. (TODO(sfiera) is fine)

[Raj, 2016/09/22 19:12:03]

Done.

   fetcher_->SetRequestContext(download_context_);
   fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                          net::LOAD_DO_NOT_SAVE_COOKIES);
   fetcher_->SetAutomaticallyRetryOnNetworkChanges(1);
   fetcher_->Start();
 }
 
 void PopularSites::OnURLFetchComplete(const net::URLFetcher* source) {
   DCHECK_EQ(fetcher_.get(), source);
   std::unique_ptr<net::URLFetcher> free_fetcher = std::move(fetcher_);
@@ skipping 82 matching lines @@
     pending_url_ = GetPopularSitesURL(kPopularSitesDefaultCountryCode,
                                       kPopularSitesDefaultVersion);
     FetchPopularSites();
   } else {
     DLOG(WARNING) << "Download fallback site list failed";
     callback_.Run(false);
   }
 }
 
 }  // namespace ntp_tiles