Basic UkmService implementation

blimp/engine/app/blimp_metrics_service_client.h

Index: blimp/engine/app/blimp_metrics_service_client.h
diff --git a/blimp/engine/app/blimp_metrics_service_client.h b/blimp/engine/app/blimp_metrics_service_client.h
index cba7d5ae464df7d89a1eb861c503b54474231121..387d9f6c8f45466227afb20e99322a19713a9fe9 100644
--- a/blimp/engine/app/blimp_metrics_service_client.h
+++ b/blimp/engine/app/blimp_metrics_service_client.h
@@ -57,6 +57,8 @@ class BlimpMetricsServiceClient : public metrics::MetricsServiceClient,
       const base::Closure& done_callback) override;
   void CollectFinalMetricsForLog(const base::Closure& done_callback) override;
   std::unique_ptr<metrics::MetricsLogUploader> CreateUploader(
+      const std::string& server_url,
+      const std::string& mime_type,
       const base::Callback<void(int)>& on_upload_complete) override;
   base::TimeDelta GetStandardUploadInterval() override;
   metrics::EnableMetricsDefault GetMetricsReportingDefaultState() override;