Remove old dead tag handler.

runtime/bin/dartutils.h

Index: runtime/bin/dartutils.h
diff --git a/runtime/bin/dartutils.h b/runtime/bin/dartutils.h
index b35ee863c32c1b01c1a4c17e70ecb752c0d56318..135d12cbc8c70b476f41d43a4fa1a9dd28a2c920 100644
--- a/runtime/bin/dartutils.h
+++ b/runtime/bin/dartutils.h
@@ -125,10 +125,6 @@ class DartUtils {
   static bool EntropySource(uint8_t* buffer, intptr_t length);
   static Dart_Handle ReadStringFromFile(const char* filename);
   static Dart_Handle MakeUint8Array(const uint8_t* buffer, intptr_t length);
-  static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag,
-                                       Dart_Handle library,
-                                       Dart_Handle url);
-  static Dart_Handle LoadScript(const char* script_uri);
   static Dart_Handle PrepareForScriptLoading(bool is_service_isolate,
                                              bool trace_loading);
   static Dart_Handle SetupServiceLoadPort();