Add server_url and mime_type params to CreateUploader.

ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm

Index: ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm
diff --git a/ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm b/ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm
index eebf25589233d03f818a05bba3bba0bb9b75d5fb..43fee09cca472b15b7f37dd14a2cf8a56941fd5d 100644
--- a/ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm
+++ b/ios/chrome/browser/metrics/ios_chrome_metrics_service_client.mm
@@ -151,11 +151,12 @@ void IOSChromeMetricsServiceClient::CollectFinalMetricsForLog(
 
 std::unique_ptr<metrics::MetricsLogUploader>
 IOSChromeMetricsServiceClient::CreateUploader(
+    const std::string& server_url,
+    const std::string& mime_type,
     const base::Callback<void(int)>& on_upload_complete) {
   return base::MakeUnique<metrics::NetMetricsLogUploader>(
       GetApplicationContext()->GetSystemURLRequestContext(),
-      metrics::kDefaultMetricsServerUrl, metrics::kDefaultMetricsMimeType,
-      on_upload_complete);
+      server_url, mime_type, on_upload_complete);
 }
 
 base::TimeDelta IOSChromeMetricsServiceClient::GetStandardUploadInterval() {