Add API to set thread name

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 0a25473aabd089d59f48d3d6d40b86d9fbbdada3..01ed58accef6608c1cda1b02d640abeeefdc0ca4 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -5958,7 +5958,7 @@ DART_EXPORT void Dart_TimelineEvent(const char* label,
   if (type < Dart_Timeline_Event_Begin) {
     return;
   }
-  if (type > Dart_Timeline_Event_Metadata) {
+  if (type > Dart_Timeline_Event_Counter) {
     return;
   }
   TimelineStream* stream = Timeline::GetEmbedderStream();
@@ -5992,9 +5992,6 @@ DART_EXPORT void Dart_TimelineEvent(const char* label,
     case Dart_Timeline_Event_Counter:
       event->Counter(label, timestamp0);
     break;
-    case Dart_Timeline_Event_Metadata:
-      event->Metadata(label, timestamp0);
-    break;
     default:
       FATAL("Unknown Dart_Timeline_Event_Type");
   }
@@ -6006,6 +6003,16 @@ DART_EXPORT void Dart_TimelineEvent(const char* label,
 }
 
 
+DART_EXPORT void Dart_SetThreadName(const char* name) {
+  OSThread* thread = OSThread::Current();
+  if (thread == NULL) {
+    // VM is shutting down.
+    return;
+  }
+  thread->SetName(name);
+}
+
+
 // The precompiler is included in dart_bootstrap and dart_noopt, and
 // excluded from dart and dart_precompiled_runtime.
 #if !defined(DART_PRECOMPILER)