Widevine Metrics System

This change is the complete Widevine metrics system. It will
measure and record runtime information about what is happening
in the CDM - such as errors and throughput.

Bug: 33745339
Bug: 26027857
Change-Id: Ic9a82074f1e2b72c72d751b235f8ae361232787d

libwvdrmengine/cdm/metrics/src/event_metric.cpp

@@ -0,0 +1,60 @@
+// Copyright 2017 Google Inc. All Rights Reserved.
+//
+// This file contains implementations for the BaseEventMetric.
+
+#include "event_metric.h"
+
+namespace wvcdm {
+namespace metrics {
+
+BaseEventMetric::~BaseEventMetric() {
+  AutoLock lock(internal_lock_);
+
+  for (std::map<std::string, Distribution*>::iterator it
+       = value_map_.begin(); it != value_map_.end(); it++) {
+    delete it->second;
+  }
+}
+
+void BaseEventMetric::Record(const std::string& field_names_values,
+                             double value) {
+  AutoLock lock(internal_lock_);
+
+  Distribution* distribution;
+
+  if (value_map_.find(field_names_values) == value_map_.end()) {
+    distribution = new Distribution();
+    value_map_[field_names_values] = distribution;
+  } else {
+    distribution = value_map_[field_names_values];
+  }
+
+  distribution->Record(value);
+}
+
+void BaseEventMetric::Publish(MetricNotification* notification) {
+  AutoLock lock(internal_lock_);
+
+  for (std::map<std::string, Distribution*>::iterator it
+       = value_map_.begin(); it != value_map_.end(); it++) {
+    notification->UpdateInt64(
+        metric_name_ + "/count" + it->first,
+        it->second->Count());
+    notification->UpdateDouble(
+        metric_name_ + "/mean" + it->first,
+        it->second->Mean());
+    notification->UpdateDouble(
+        metric_name_ + "/variance" + it->first,
+        it->second->Variance());
+    notification->UpdateDouble(
+        metric_name_ + "/min" + it->first,
+        it->second->Min());
+    notification->UpdateDouble(
+        metric_name_ + "/max" + it->first,
+        it->second->Max());
+  }
+}
+
+}  // namespace metrics
+}  // namespace wvcdm
+