Add data usage tracking for GAIA auth api

components/data_use_measurement/core/data_use_user_data.cc

Index: components/data_use_measurement/core/data_use_user_data.cc
diff --git a/components/data_use_measurement/core/data_use_user_data.cc b/components/data_use_measurement/core/data_use_user_data.cc
index 32fe798e1af231831bcb69fc770df5e9afe7b357..b467a3c570bd2c89da1e89cacce21a08ea40eb37 100644
--- a/components/data_use_measurement/core/data_use_user_data.cc
+++ b/components/data_use_measurement/core/data_use_user_data.cc
@@ -110,6 +110,8 @@ std::string DataUseUserData::GetServiceNameAsString(ServiceName service_name) {
       return "SupervisedUser";
     case IMAGE_FETCHER_UNTAGGED:
       return "ImageFetcherUntagged";
+    case GAIA:
+      return "GAIA";
   }
   return "INVALID";
 }