common: Split out metrics utils from utils.cc.

The utility functions to convert error codes and network settings to
the types defined by the metrics framework are split out the utils.cc
file. These tools are only used by the update_engine daemon to report
back metrics on an update check.

Bug: 25197634
Test: FEATURES=test emerge-link update_engine; mma

Change-Id: I589dc9f6056fb1399fa84ca4f44076ed3a6b5365
diff --git a/metrics_utils.h b/metrics_utils.h
new file mode 100644
index 0000000..1b8d8ac
--- /dev/null
+++ b/metrics_utils.h
@@ -0,0 +1,45 @@
+//
+// Copyright (C) 2015 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef UPDATE_ENGINE_METRICS_UTILS_H_
+#define UPDATE_ENGINE_METRICS_UTILS_H_
+
+#include "update_engine/connection_manager.h"
+#include "update_engine/metrics.h"
+
+namespace chromeos_update_engine {
+namespace metrics_utils {
+
+// Transforms a ErrorCode value into a metrics::DownloadErrorCode.
+// This obviously only works for errors related to downloading so if |code|
+// is e.g. |ErrorCode::kFilesystemCopierError| then
+// |kDownloadErrorCodeInputMalformed| is returned.
+metrics::DownloadErrorCode GetDownloadErrorCode(ErrorCode code);
+
+// Transforms a ErrorCode value into a metrics::AttemptResult.
+//
+// If metrics::AttemptResult::kPayloadDownloadError is returned, you
+// can use utils::GetDownloadError() to get more detail.
+metrics::AttemptResult GetAttemptResult(ErrorCode code);
+
+// Calculates the internet connection type given |type| and |tethering|.
+metrics::ConnectionType GetConnectionType(NetworkConnectionType type,
+                                          NetworkTethering tethering);
+
+}  // namespace metrics_utils
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_METRICS_UTILS_H_