Gauge metric producer.

Test: manual tests passed for pushed device temperature.
Change-Id: I7592a4c04666606b745cdb41db8f9d8a96a966da
diff --git a/cmds/statsd/tests/MetricsManager_test.cpp b/cmds/statsd/tests/MetricsManager_test.cpp
index e8e4d8b..7333785 100644
--- a/cmds/statsd/tests/MetricsManager_test.cpp
+++ b/cmds/statsd/tests/MetricsManager_test.cpp
@@ -17,6 +17,7 @@
 #include "src/condition/ConditionTracker.h"
 #include "src/matchers/LogMatchingTracker.h"
 #include "src/metrics/CountMetricProducer.h"
+#include "src/metrics/GaugeMetricProducer.h"
 #include "src/metrics/MetricProducer.h"
 #include "src/metrics/ValueMetricProducer.h"
 #include "src/metrics/metrics_manager_util.h"