Move no_callback_scope_depth_ and cha_ from isolate -> thread

runtime/vm/object.cc

 // 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.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 1808 matching lines @@
 #endif
 }
 
 
 RawObject* Object::Allocate(intptr_t cls_id,
                             intptr_t size,
                             Heap::Space space) {
   ASSERT(Utils::IsAligned(size, kObjectAlignment));
   Thread* thread = Thread::Current();
   Isolate* isolate = thread->isolate();
-  ASSERT(isolate->no_callback_scope_depth() == 0);
+  // New space allocation allowed only in mutator thread (Dart thread);
+  ASSERT(isolate->MutatorThreadIsCurrentThread() || (space != Heap::kNew));
+  ASSERT(thread->no_callback_scope_depth() == 0);
   Heap* heap = isolate->heap();
 
   uword address = heap->Allocate(size, space);
   if (address == 0) {
     // Use the preallocated out of memory exception to avoid calling
     // into dart code or allocating any code.
     const Instance& exception =
         Instance::Handle(isolate->object_store()->out_of_memory());
     Exceptions::Throw(thread, exception);
     UNREACHABLE();
@@ skipping 19726 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart