Refactor 'dart:profiler' UserTag API

runtime/vm/dart.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/dart.h"
 
 #include "vm/code_observers.h"
 #include "vm/cpu.h"
 #include "vm/dart_api_state.h"
 #include "vm/dart_entry.h"
@@ skipping 249 matching lines @@
   Api::SetupAcquiredError(isolate);
   if (FLAG_print_class_table) {
     isolate->class_table()->Print();
   }
 
 
   Service::SendIsolateStartupMessage();
   // Create tag table.
   isolate->set_tag_table(
       GrowableObjectArray::Handle(GrowableObjectArray::New()));
+  // Set up default UserTag.
+  const UserTag& default_tag = UserTag::Handle(UserTag::DefaultTag());
+  isolate->set_current_tag(default_tag);
+
   return Error::null();
 }
 
 
 void Dart::RunShutdownCallback() {
   Isolate* isolate = Isolate::Current();
   void* callback_data = isolate->init_callback_data();
   Dart_IsolateShutdownCallback callback = Isolate::ShutdownCallback();
   Service::SendIsolateShutdownMessage();
   if (callback != NULL) {
@@ skipping 15 matching lines @@
   return predefined_handles_->handles_.AllocateScopedHandle();
 }
 
 
 bool Dart::IsReadOnlyHandle(uword address) {
   ASSERT(predefined_handles_ != NULL);
   return predefined_handles_->handles_.IsValidScopedHandle(address);
 }
 
 }  // namespace dart