Migrate handle scope fields to Thread.

runtime/vm/thread_test.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 "platform/assert.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
 #include "vm/unit_test.h"
 #include "vm/profiler.h"
 #include "vm/thread_pool.h"
@@ skipping 99 matching lines @@
  public:
   TaskWithZoneAllocation(Isolate* isolate,
                          const String& foo,
                          Monitor* monitor,
                          bool* done,
                          intptr_t id)
       : isolate_(isolate), foo_(foo), monitor_(monitor), done_(done), id_(id) {}
   virtual void Run() {
     Thread::EnterIsolateAsHelper(isolate_);
     {
+      Thread* thread = Thread::Current();
       // Create a zone (which is also a stack resource) and exercise it a bit.
-      StackZone stack_zone(Thread::Current());
-      Zone* zone = Thread::Current()->zone();
+      StackZone stack_zone(thread);
+      HANDLESCOPE(thread);
+      Zone* zone = thread->zone();
       EXPECT_EQ(zone, stack_zone.GetZone());
       ZoneGrowableArray<bool>* a0 = new(zone) ZoneGrowableArray<bool>(zone, 1);
       GrowableArray<bool> a1(zone, 1);
       for (intptr_t i = 0; i < 100000; ++i) {
         a0->Add(true);
         a1.Add(true);
       }
       // Check that we can create handles (but not yet allocate heap objects).
       String& str = String::Handle(zone, foo_.raw());
       EXPECT(str.Equals("foo"));
@@ skipping 83 matching lines @@
   Thread::ExitIsolate();
   Thread::EnterIsolate(orig);
   // Original zone should be preserved.
   EXPECT_EQ(orig_zone, Thread::Current()->zone());
   EXPECT_STREQ("foo", orig_str);
   delete isos[0];
   delete isos[1];
 }
 
 }  // namespace dart