Refactor 'dart:profiler' UserTag API

runtime/vm/object.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 6858 matching lines @@
     ASSERT(t < UserTags::kUserTagIdOffset + UserTags::kMaxUserTags);
     raw_ptr()->tag_ = t;
   };
   static intptr_t tag_offset() { return OFFSET_OF(RawUserTag, tag_); }
 
   RawString* label() const {
     return raw_ptr()->label_;
   }
 
   void MakeActive() const;
-  static void ClearActive();
 
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawUserTag));
   }
 
   static RawUserTag* New(const String& label,
                          Heap::Space space = Heap::kOld);
+  static RawUserTag* DefaultTag();
 
   static bool TagTableIsFull(Isolate* isolate);
   static RawUserTag* FindTagById(uword tag_id);
 
  private:
   static RawUserTag* FindTagInIsolate(Isolate* isolate, const String& label);
   static void AddTagToIsolate(Isolate* isolate, const UserTag& tag);
 
   void set_label(const String& tag_label) const {
     StorePointer(&raw_ptr()->label_, tag_label.raw());
@@ skipping 137 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_