Do not start sampler thread when CpuProfiler is active

src/sampler.h

 // Copyright 2013 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 81 matching lines @@
 
   // Start and stop sampler.
   void Start();
   void Stop();
 
   // Whether the sampling thread should use this Sampler for CPU profiling?
   bool IsProfiling() const {
     return NoBarrier_Load(&profiling_) > 0 &&
         !NoBarrier_Load(&has_processing_thread_);
   }
-  void IncreaseProfilingDepth() { NoBarrier_AtomicIncrement(&profiling_, 1); }
-  void DecreaseProfilingDepth() { NoBarrier_AtomicIncrement(&profiling_, -1); }
+  void IncreaseProfilingDepth();
+  void DecreaseProfilingDepth();
 
   // Whether the sampler is running (that is, consumes resources).
   bool IsActive() const { return NoBarrier_Load(&active_); }
 
+  void DoSample();
   // If true next sample must be initiated on the profiler event processor
   // thread right after latest sample is processed.
-  static bool CanSampleOnProfilerEventsProcessorThread();
-  void DoSample();
   void SetHasProcessingThread(bool value) {
     NoBarrier_Store(&has_processing_thread_, value);
   }
 
   // Used in tests to make sure that stack sampling is performed.
   unsigned js_and_external_sample_count() const {
     return js_and_external_sample_count_;
   }
   void StartCountingSamples() {
       is_counting_samples_ = true;
@@ skipping 20 matching lines @@
   bool is_counting_samples_;
   // Counts stack samples taken in JS VM state.
   unsigned js_and_external_sample_count_;
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SAMPLER_H_