metrics_daemon: log to syslog

Also log to stderr when not running as daemon.

BUG=chromium:364700
TEST=manually verified in both daemon and non-daemon modes

Change-Id: If62f70c1d327a5ecaf3075b6689b83a1494c09d5
Reviewed-on: https://chromium-review.googlesource.com/199380
Tested-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Daniel Erat <derat@chromium.org>
Commit-Queue: Luigi Semenzato <semenzato@chromium.org>
diff --git a/metrics_daemon.cc b/metrics_daemon.cc
index 47d74fa..d1eb25e 100644
--- a/metrics_daemon.cc
+++ b/metrics_daemon.cc
@@ -928,8 +928,6 @@
 
 void MetricsDaemon::SendSample(const string& name, int sample,
                                int min, int max, int nbuckets) {
-  DLOG(INFO) << "received metric: " << name << " " << sample << " "
-             << min << " " << max << " " << nbuckets;
   metrics_lib_->SendToUMA(name, sample, min, max, nbuckets);
 }
 
@@ -993,8 +991,6 @@
 
 void MetricsDaemon::SendLinearSample(const string& name, int sample,
                                      int max, int nbuckets) {
-  DLOG(INFO) << "received linear metric: " << name << " " << sample << " "
-             << max << " " << nbuckets;
   // TODO(semenzato): add a proper linear histogram to the Chrome external
   // metrics API.
   LOG_IF(FATAL, nbuckets != max + 1) << "unsupported histogram scale";
diff --git a/metrics_daemon_main.cc b/metrics_daemon_main.cc
index 5fb7507..ffe74f2 100644
--- a/metrics_daemon_main.cc
+++ b/metrics_daemon_main.cc
@@ -3,8 +3,10 @@
 // found in the LICENSE file.
 
 
+#include <base/command_line.h>
 #include <base/logging.h>
 #include <base/strings/string_util.h>
+#include <chromeos/syslog_logging.h>
 #include <gflags/gflags.h>
 #include <rootdev/rootdev.h>
 
@@ -43,7 +45,13 @@
 }
 
 int main(int argc, char** argv) {
+  CommandLine::Init(argc, argv);
   google::ParseCommandLineFlags(&argc, &argv, true);
+
+  // Also log to stderr when not running as daemon.
+  chromeos::InitLog(chromeos::kLogToSyslog | chromeos::kLogHeader |
+                    (FLAGS_daemon ? 0 : chromeos::kLogToStderr));
+
   MetricsLibrary metrics_lib;
   metrics_lib.Init();
   MetricsDaemon daemon;