Allow server endpoint to be injected into the NetMetricsLogUploader from chrome/

components/metrics/url_constants.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_METRICS_URL_CONSTANTS_H_
+#define COMPONENTS_METRICS_URL_CONSTANTS_H_
+
+namespace metrics {
+
+// The default metrics server's URL.
+extern const char kDefaultMetricsServerUrl[];
+
+// The default MIME type for the uploaded metrics data.
+extern const char kDefaultMetricsMimeType[];
+
+} // namespace metrics
+
+#endif // COMPONENTS_METRICS_URL_CONSTANTS_H_