Do not start sampler thread when CpuProfiler is active

src/cpu-profiler.h

 // Copyright 2012 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 145 matching lines @@
   // next record of the buffer.
   inline TickSample* StartTickSample();
   inline void FinishTickSample();
 
  private:
   // Called from events processing thread (Run() method.)
   bool ProcessCodeEvent();
   bool ProcessTicks();
 
   void ProcessEventsAndDoSample();
-  void ProcessEventsAndYield();
 
   ProfileGenerator* generator_;
   Sampler* sampler_;
   bool running_;
   // Sampling period in microseconds.
   const TimeDelta period_;
   UnboundQueue<CodeEventsContainer> events_buffer_;
   static const size_t kTickSampleBufferSize = 1 * MB;
   static const size_t kTickSampleQueueLength =
       kTickSampleBufferSize / sizeof(TickSampleEventRecord);
@@ skipping 82 matching lines @@
   void StopProcessor();
   void ResetProfiles();
   void LogBuiltins();
 
   Isolate* isolate_;
   CpuProfilesCollection* profiles_;
   unsigned next_profile_uid_;
   ProfileGenerator* generator_;
   ProfilerEventsProcessor* processor_;
   bool saved_is_logging_;
-  bool need_to_stop_sampler_;
   bool is_profiling_;
 
   DISALLOW_COPY_AND_ASSIGN(CpuProfiler);
 };
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_CPU_PROFILER_H_