Log the thermal throttling event to enable conditional temperature pulling.

Test: statsd test

BUG: b/112432890

Change-Id: If132bab9690043a9e3e89187dfb1a9ed8fd0c996
diff --git a/bin/src/atoms.proto b/bin/src/atoms.proto
index 2c07431..3bd1bb0 100644
--- a/bin/src/atoms.proto
+++ b/bin/src/atoms.proto
@@ -132,6 +132,7 @@
         KeyValuePairsAtom key_value_pairs_atom = 83;
         VibratorStateChanged vibrator_state_changed = 84;
         DeferredJobStatsReported deferred_job_stats_reported = 85;
+        ThermalThrottlingStateChanged thermal_throttling = 86;
     }
 
     // Pulled events will start at field 10000.
@@ -229,6 +230,26 @@
  */
 
 /**
+ * Logs when the Thermal service HAL notifies the throttling start/stop events.
+ *
+ * Logged from:
+ *   frameworks/base/services/core/java/com/android/server/stats/StatsCompanionService.java
+ */
+message ThermalThrottlingStateChanged {
+    optional android.os.TemperatureTypeEnum sensor_type = 1;
+
+    enum State {
+        UNKNOWN = 0;
+        START = 1;
+        STOP = 2;
+    }
+
+    optional State state = 2;
+
+    optional float temperature = 3;
+}
+
+/**
  * Logs when the screen state changes.
  *
  * Logged from: