Add multithreading test for SamplingCircularQueue, fix implementation.

src/cpu-profiler.cc

 // Copyright 2010 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 158 matching lines @@
       generator_->RecordTickSample(rec->sample);
       ticks_buffer_.FinishDequeue();
     } else {
       return true;
     }
   }
 }
 
 
 void ProfilerEventsProcessor::Run() {
-  ticks_buffer_.SetUpConsumer();
   unsigned dequeue_order = 0;
   running_ = true;
 
   while (running_) {
     // Process ticks until we have any.
     if (ProcessTicks(dequeue_order)) {
       // All ticks of the current dequeue_order are processed,
       // proceed to the next code event.
       ProcessCodeEvent(&dequeue_order);
     }
     YieldCPU();
   }
 
   // Process remaining tick events.
   ticks_buffer_.FlushResidualRecords();
   // Perform processing until we have tick events, skip remaining code events.
   while (ProcessTicks(dequeue_order) && ProcessCodeEvent(&dequeue_order)) { }
-  ticks_buffer_.TearDownConsumer();
 }
 
 
 } }  // namespace v8::internal