Add data usage tracking for image fetcher service

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 fb57555a45f8d2ec6eb93ab0da98348be455f8e2..28385484c14ce469298153f6d27d998f04ccc20a 100644
--- a/components/data_use_measurement/core/data_use_user_data.cc
+++ b/components/data_use_measurement/core/data_use_user_data.cc
@@ -108,8 +108,10 @@ std::string DataUseUserData::GetServiceNameAsString(ServiceName service_name) {
       return "NetworkTimeTracker";
     case SUPERVISED_USER:
       return "SupervisedUser";
+    case IMAGE_FETCHER_UNTAGGED:
+      return "Image Fetcher Untagged";
   }
-  return "INVALID";
+  NOTREACHED();
 }
 
 // static