Add data usage tracking for GAIA auth api and GCM engine service

google_apis/gcm/engine/registration_request.cc

Index: google_apis/gcm/engine/registration_request.cc
diff --git a/google_apis/gcm/engine/registration_request.cc b/google_apis/gcm/engine/registration_request.cc
index 386af0e7eab3f55967901e5e066684f10acaaf75..bcc99008b2e1c0654abd8e49f459c615a75c8a5b 100644
--- a/google_apis/gcm/engine/registration_request.cc
+++ b/google_apis/gcm/engine/registration_request.cc
@@ -15,6 +15,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
+#include "components/data_use_measurement/core/data_use_user_data.h"
 #include "google_apis/gcm/base/gcm_util.h"
 #include "google_apis/gcm/monitoring/gcm_stats_recorder.h"
 #include "net/base/load_flags.h"
@@ -150,6 +151,8 @@ void RegistrationRequest::Start() {
   url_fetcher_->SetRequestContext(request_context_getter_.get());
   url_fetcher_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                              net::LOAD_DO_NOT_SAVE_COOKIES);
+  data_use_measurement::DataUseUserData::AttachToFetcher(
+      url_fetcher_.get(), data_use_measurement::DataUseUserData::GCM_ENGINE);
 
   std::string extra_headers;
   BuildRequestHeaders(&extra_headers);