remove HEAP from tests

test/cctest/test-threads.cc

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 99 matching lines @@
     do {
       {
         v8::Isolate* isolate = CcTest::default_isolate();
         v8::Locker locker(isolate);
         if (turn == CLEAN_CACHE) {
           v8::HandleScope scope(isolate);
           v8::Handle<v8::Context> context = v8::Context::New(isolate);
           v8::Context::Scope context_scope(context);
 
           // Clear the caches by forcing major GC.
-          HEAP->CollectAllGarbage(v8::internal::Heap::kNoGCFlags);
+          CcTest::heap()->CollectAllGarbage(v8::internal::Heap::kNoGCFlags);
           turn = SECOND_TIME_FILL_CACHE;
           break;
         }
       }
 
       Thread::YieldCPU();
     } while (true);
   }
 };
 
@@ skipping 75 matching lines @@
     Join();
   }
 };
 
 
 TEST(ThreadJoinSelf) {
   ThreadC thread;
   thread.Start();
   thread.Join();
 }