[heap] Disable concurrent marking for cctests that rely on manual GC.

test/cctest/heap/test-array-buffer-tracker.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 #include "src/heap/array-buffer-tracker.h"
 #include "src/heap/spaces.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 #include "test/cctest/cctest.h"
@@ skipping 96 matching lines @@
     Page::FromAddress(buf->address())->MarkNeverEvacuate();
   }
   // 2 GCs are needed because we promote to old space as live, meaning that
   // we will survive one GC.
   heap::GcAndSweep(heap, OLD_SPACE);
   heap::GcAndSweep(heap, OLD_SPACE);
   CHECK(!IsTracked(raw_ab));
 }
 
 TEST(ArrayBuffer_Compaction) {
+  FLAG_concurrent_marking = false;
   FLAG_stress_incremental_marking = false;
   FLAG_manual_evacuation_candidates_selection = true;
   CcTest::InitializeVM();
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
   Heap* heap = reinterpret_cast<Isolate*>(isolate)->heap();
   heap::AbandonCurrentlyFreeMemory(heap->old_space());
 
   v8::HandleScope handle_scope(isolate);
   Local<v8::ArrayBuffer> ab1 = v8::ArrayBuffer::New(isolate, 100);
@@ skipping 196 matching lines @@
     Local<v8::ArrayBuffer> ab2 = v8::ArrayBuffer::New(isolate, 100);
     Handle<JSArrayBuffer> buf2 = v8::Utils::OpenHandle(*ab2);
     CHECK_NE(Page::FromAddress(buf1->address()),
              Page::FromAddress(buf2->address()));
     heap::GcAndSweep(heap, OLD_SPACE);
   }
 }
 
 }  // namespace internal
 }  // namespace v8