Mojo: Add basic logging facilities to environment.

mojo/public/cpp/environment/tests/logger_unittest.cc

+// Copyright 2014 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.
+
+#include "mojo/public/cpp/environment/default_logger.h"
+#include "mojo/public/cpp/environment/environment.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace {
+
+TEST(LoggerTest, Basic) {
+  Environment environment;
+  const MojoLogger* const logger = GetDefaultLogger();
+
+  logger->LogMessage(MOJO_LOG_LEVEL_VERBOSE-1, "Logged at VERBOSE-1 level");
+  logger->LogMessage(MOJO_LOG_LEVEL_VERBOSE, "Logged at VERBOSE level");
+  logger->LogMessage(MOJO_LOG_LEVEL_INFO, "Logged at INFO level");
+  logger->LogMessage(MOJO_LOG_LEVEL_WARNING, "Logged at WARNING level");
+  logger->LogMessage(MOJO_LOG_LEVEL_ERROR, "Logged at ERROR level");
+
+  // This should kill us:
+  EXPECT_DEATH({
+    logger->LogMessage(MOJO_LOG_LEVEL_FATAL, "Logged at FATAL level");
+  }, "");
+}
+
+}  // namespace
+}  // namespace mojo