diff --git a/libmetricslogger/Android.bp b/libmetricslogger/Android.bp
index 6549b8d56..e6e17ce87 100644
--- a/libmetricslogger/Android.bp
+++ b/libmetricslogger/Android.bp
@@ -29,6 +29,13 @@ cc_library_shared {
     defaults: ["metricslogger_defaults"],
 }
 
+// static version of libmetricslogger, needed by a few art static binaries
+cc_library_static {
+    name: "libmetricslogger_static",
+    srcs: metricslogger_lib_src_files,
+    defaults: ["metricslogger_defaults"],
+}
+
 // metricslogger shared library, debug
 // -----------------------------------------------------------------------------
 cc_library_shared {
diff --git a/libmetricslogger/include/metricslogger/metrics_logger.h b/libmetricslogger/include/metricslogger/metrics_logger.h
index 189bc4b63..2c768695d 100644
--- a/libmetricslogger/include/metricslogger/metrics_logger.h
+++ b/libmetricslogger/include/metricslogger/metrics_logger.h
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <log/log_event_list.h>
 #include <cstdint>
 #include <string>
 
@@ -32,6 +33,34 @@ void LogCounter(const std::string& name, int32_t val);
 // |value| in the field |field|.
 void LogMultiAction(int32_t category, int32_t field, const std::string& value);
 
+// Logs a Tron complex event.
+//
+// A complex event can include data in a structure not suppored by the other
+// log event types above.
+//
+// Note that instances of this class are single use. You must call Record()
+// to write the event to the event log.
+class ComplexEventLogger {
+  private:
+    android_log_event_list logger;
+
+  public:
+    // Create a complex event with category|category|.
+    explicit ComplexEventLogger(int category);
+    // Add tagged data to the event, with the given tag and integer value.
+    void AddTaggedData(int tag, int32_t value);
+    // Add tagged data to the event, with the given tag and string value.
+    void AddTaggedData(int tag, const std::string& value);
+    // Add tagged data to the event, with the given tag and integer value.
+    void AddTaggedData(int tag, int64_t value);
+    // Add tagged data to the event, with the given tag and float value.
+    void AddTaggedData(int tag, float value);
+    // Record this event. This method can only be used once per instance
+    // of ComplexEventLogger. Do not made any subsequent calls to AddTaggedData
+    // after recording an event.
+    void Record();
+};
+
 // TODO: replace these with the metric_logger.proto definitions
 enum {
     LOGBUILDER_CATEGORY = 757,
@@ -44,11 +73,23 @@ enum {
 
     ACTION_BOOT = 1098,
     FIELD_PLATFORM_REASON = 1099,
+
+    ACTION_HIDDEN_API_ACCESSED = 1391,
+    FIELD_HIDDEN_API_ACCESS_METHOD = 1392,
+    FIELD_HIDDEN_API_ACCESS_DENIED = 1393,
+    FIELD_HIDDEN_API_SIGNATURE = 1394,
 };
 
 enum {
     TYPE_ACTION = 4,
 };
 
+enum {
+    ACCESS_METHOD_NONE = 0,
+    ACCESS_METHOD_REFLECTION = 1,
+    ACCESS_METHOD_JNI = 2,
+    ACCESS_METHOD_LINKING = 3,
+};
+
 }  // namespace metricslogger
 }  // namespace android
diff --git a/libmetricslogger/metrics_logger.cpp b/libmetricslogger/metrics_logger.cpp
index fdc44071b..912fa1281 100644
--- a/libmetricslogger/metrics_logger.cpp
+++ b/libmetricslogger/metrics_logger.cpp
@@ -23,9 +23,14 @@
 
 namespace {
 
+#ifdef __ANDROID__
 EventTagMap* kEventTagMap = android_openEventTagMap(nullptr);
 const int kSysuiMultiActionTag = android_lookupEventTagNum(
     kEventTagMap, "sysui_multi_action", "(content|4)", ANDROID_LOG_UNKNOWN);
+#else
+// android_openEventTagMap does not work on host builds.
+const int kSysuiMultiActionTag = 0;
+#endif
 
 }  // namespace
 
@@ -53,5 +58,29 @@ void LogMultiAction(int32_t category, int32_t field, const std::string& value) {
         << field << value << LOG_ID_EVENTS;
 }
 
+ComplexEventLogger::ComplexEventLogger(int category) : logger(kSysuiMultiActionTag) {
+    logger << LOGBUILDER_CATEGORY << category;
+}
+
+void ComplexEventLogger::AddTaggedData(int tag, int32_t value) {
+    logger << tag << value;
+}
+
+void ComplexEventLogger::AddTaggedData(int tag, const std::string& value) {
+    logger << tag << value;
+}
+
+void ComplexEventLogger::AddTaggedData(int tag, int64_t value) {
+    logger << tag << value;
+}
+
+void ComplexEventLogger::AddTaggedData(int tag, float value) {
+    logger << tag << value;
+}
+
+void ComplexEventLogger::Record() {
+    logger << LOG_ID_EVENTS;
+}
+
 }  // namespace metricslogger
 }  // namespace android
diff --git a/logcat/event.logtags b/logcat/event.logtags
index 7c40a777a..750761f42 100644
--- a/logcat/event.logtags
+++ b/logcat/event.logtags
@@ -67,8 +67,9 @@
 # ZygoteInit class preloading ends:
 3030 boot_progress_preload_end (time|2|3)
 
-# Dalvik VM
+# Dalvik VM / ART
 20003 dvm_lock_sample (process|3),(main|1|5),(thread|3),(time|1|3),(file|3),(line|1|5),(ownerfile|3),(ownerline|1|5),(sample_percent|1|6)
+20004 art_hidden_api_access (access_method|1),(flags|1),(class|3),(member|3),(type_signature|3)
 
 75000 sqlite_mem_alarm_current (current|1|2)
 75001 sqlite_mem_alarm_max (max|1|2)