Migrate NoSafepointScope; add constrained concurrent allocation to unit test

runtime/vm/object_graph.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/object_graph.h"
 
 #include "vm/dart.h"
 #include "vm/growable_array.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 238 matching lines @@
   intptr_t size_excluding_class = excluding_class.size();
   return size_total - size_excluding_class;
 }
 
 
 class RetainingPathVisitor : public ObjectGraph::Visitor {
  public:
   // We cannot use a GrowableObjectArray, since we must not trigger GC.
   RetainingPathVisitor(RawObject* obj, const Array& path)
       : obj_(obj), path_(path), length_(0) {
-    ASSERT(Isolate::Current()->no_safepoint_scope_depth() != 0);
+    ASSERT(Thread::Current()->no_safepoint_scope_depth() != 0);
   }
 
   intptr_t length() const { return length_; }
 
   virtual Direction VisitObject(ObjectGraph::StackIterator* it) {
     if (it->Get() != obj_) {
       return kProceed;
     } else {
       HANDLESCOPE(Isolate::Current());
       Object& current = Object::Handle();
@@ skipping 36 matching lines @@
 class InboundReferencesVisitor : public ObjectVisitor,
                                  public ObjectPointerVisitor {
  public:
   // We cannot use a GrowableObjectArray, since we must not trigger GC.
   InboundReferencesVisitor(Isolate* isolate,
                            RawObject* target,
                            const Array& references,
                            Object* scratch)
     : ObjectVisitor(isolate), ObjectPointerVisitor(isolate), source_(NULL),
       target_(target), references_(references), scratch_(scratch), length_(0) {
-    ASSERT(Isolate::Current()->no_safepoint_scope_depth() != 0);
+    ASSERT(Thread::Current()->no_safepoint_scope_depth() != 0);
   }
 
   intptr_t length() const { return length_; }
 
   virtual void VisitObject(RawObject* raw_obj) {
     source_ = raw_obj;
     raw_obj->VisitPointers(this);
   }
 
   virtual void VisitPointers(RawObject** first, RawObject** last) {
@@ skipping 130 matching lines @@
   {
     WritePointerVisitor ptr_writer(isolate(), stream);
     isolate()->IterateObjectPointers(&ptr_writer, false, false);
   }
   stream->WriteUnsigned(0);
   IterateObjects(&visitor);
   return visitor.count() + 1;  // + root
 }
 
 }  // namespace dart