Added methods to surface number of zone and scoped handles for each isolate.

runtime/vm/isolate.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/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 2026 matching lines @@
       }
     }
     jsobj.AddProperty("pauseEvent", &pause_event);
   }
 
   const Library& lib = Library::Handle(object_store()->root_library());
   if (!lib.IsNull()) {
     jsobj.AddProperty("rootLib", lib);
   }
 
+  intptr_t zone_handle_count = thread_registry_->CountZoneHandles();
+  intptr_t scoped_handle_count = thread_registry_->CountScopedHandles();
+
+  jsobj.AddProperty("_numZoneHandles", zone_handle_count);
+  jsobj.AddProperty("_numScopedHandles", scoped_handle_count);
+
   if (FLAG_profiler) {
     JSONObject tagCounters(&jsobj, "_tagCounters");
     vm_tag_counters()->PrintToJSONObject(&tagCounters);
   }
   if (Thread::Current()->sticky_error() != Object::null()) {
     Error& error = Error::Handle(Thread::Current()->sticky_error());
     ASSERT(!error.IsNull());
     jsobj.AddProperty("error", error, false);
   } else if (sticky_error() != Object::null()) {
     Error& error = Error::Handle(sticky_error());
@@ skipping 891 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart