Revert "Thread-safe metric producers."

This reverts commit 8de6939c494da838f6dbbda0631f66425dbbd25b.

Change-Id: Ieae841bfc5339b569f0fca909a6066de72806617
diff --git a/cmds/statsd/src/metrics/ValueMetricProducer.h b/cmds/statsd/src/metrics/ValueMetricProducer.h
index e87e9da..a024bd8 100644
--- a/cmds/statsd/src/metrics/ValueMetricProducer.h
+++ b/cmds/statsd/src/metrics/ValueMetricProducer.h
@@ -72,16 +72,6 @@
     void startNewProtoOutputStream(long long timestamp) override;
 
 private:
-    void onMatchedLogEventInternal_pull(const uint64_t& eventTimeNs,
-                                        const HashableDimensionKey& eventKey, const long& value,
-                                        bool scheduledPull);
-    void onMatchedLogEventInternal_push(const uint64_t& eventTimeNs,
-                                        const HashableDimensionKey& eventKey, const long& value);
-
-    void SerializeBuckets();
-
-    bool IsConditionMet() const;
-
     const ValueMetric mMetric;
 
     std::shared_ptr<StatsPullerManager> mStatsPullerManager;
@@ -92,6 +82,8 @@
                         const int pullTagId, const uint64_t startTimeNs,
                         std::shared_ptr<StatsPullerManager> statsPullerManager);
 
+    Mutex mLock;
+
     // tagId for pulled data. -1 if this is not pulled
     const int mPullTagId;
 
@@ -110,7 +102,7 @@
     // TODO: Add a lock to mPastBuckets.
     std::unordered_map<HashableDimensionKey, std::vector<ValueBucket>> mPastBuckets;
 
-    long get_value(const LogEvent& event) const;
+    long get_value(const LogEvent& event);
 
     bool hitGuardRail(const HashableDimensionKey& newKey);