Fix memory leak in CPU Profile page

runtime/vm/tags.cc

 // Copyright (c) 2014, 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/tags.h"
 
 #include "vm/isolate.h"
 #include "vm/json_stream.h"
 #include "vm/native_entry.h"
 #include "vm/runtime_entry.h"
@@ skipping 15 matching lines @@
   }
   ASSERT(tag != kInvalidTagId);
   ASSERT(tag < kNumVMTags);
   const TagEntry& entry = entries_[tag];
   ASSERT(entry.id == tag);
   return entry.name;
 }
 
 
 bool VMTag::IsNativeEntryTag(uword tag) {
-  if (tag == 0) {
+  if ((tag == kRootTagId) || (tag == kTruncatedTagId)) {
     return false;
   }
   ASSERT(tag != kInvalidTagId);
   ASSERT(tag != kNumVMTags);
+  ASSERT(tag != kLastTagId);
   return (tag > kNumVMTags) && !IsRuntimeEntryTag(tag);
 }
 
 static RuntimeEntry* runtime_entry_list = NULL;
 
 bool VMTag::IsRuntimeEntryTag(uword id) {
   const RuntimeEntry* current = runtime_entry_list;
   while (current != NULL) {
     if (reinterpret_cast<uword>(current->function()) == id) {
       return true;
@@ skipping 98 matching lines @@
   Isolate* isolate = Isolate::Current();
   const UserTag& tag =
       UserTag::Handle(isolate, UserTag::FindTagById(tag_id));
   ASSERT(!tag.IsNull());
   const String& label = String::Handle(isolate, tag.label());
   return label.ToCString();
 }
 
 
 }  // namespace dart