logd: Add pidToUid helper

Change-Id: I23ebae1957c027bff6cbc2573a227bf0c44c08a2
diff --git a/logd/LogBuffer.h b/logd/LogBuffer.h
index 7c57660..bdb3179 100644
--- a/logd/LogBuffer.h
+++ b/logd/LogBuffer.h
@@ -79,6 +79,7 @@
 
     // helper
     char *pidToName(pid_t pid) { return stats.pidToName(pid); }
+    uid_t pidToUid(pid_t pid) { return stats.pidToUid(pid); }
 
 private:
     void maybePrune(log_id_t id);