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

google_apis/gaia/gaia_oauth_client.cc

Index: google_apis/gaia/gaia_oauth_client.cc
diff --git a/google_apis/gaia/gaia_oauth_client.cc b/google_apis/gaia/gaia_oauth_client.cc
index 5fe761055c76de25703a82d160bf7589b1872071..f0bd6dbc82d927ef18d004ec37b15f051535a997 100644
--- a/google_apis/gaia/gaia_oauth_client.cc
+++ b/google_apis/gaia/gaia_oauth_client.cc
@@ -11,6 +11,7 @@
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
+#include "components/data_use_measurement/core/data_use_user_data.h"
 #include "google_apis/gaia/gaia_urls.h"
 #include "net/base/escape.h"
 #include "net/base/load_flags.h"
@@ -183,6 +184,8 @@ void GaiaOAuthClient::Core::GetUserInfoImpl(
   request_->SetMaxRetriesOn5xx(max_retries);
   request_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                          net::LOAD_DO_NOT_SAVE_COOKIES);
+  data_use_measurement::DataUseUserData::AttachToFetcher(
+      request_.get(), data_use_measurement::DataUseUserData::GAIA_AUTH_FETCHER);
 
   // Fetchers are sometimes cancelled because a network change was detected,
   // especially at startup and after sign-in on ChromeOS. Retrying once should