Improve test-cpu-profiler.cc tests stability

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 85 matching lines @@
 
   // Is the sampler used for profiling?
   bool IsProfiling() const { return NoBarrier_Load(&profiling_) > 0; }
   void IncreaseProfilingDepth() { NoBarrier_AtomicIncrement(&profiling_, 1); }
   void DecreaseProfilingDepth() { NoBarrier_AtomicIncrement(&profiling_, -1); }
 
   // Whether the sampler is running (that is, consumes resources).
   bool IsActive() const { return NoBarrier_Load(&active_); }
 
   // Used in tests to make sure that stack sampling is performed.
-  int samples_taken() const { return samples_taken_; }
-  void ResetSamplesTaken() { samples_taken_ = 0; }
+  unsigned js_and_external_sample_count() const {
+    return js_and_external_sample_count_;
+  }
+  void StartCountingSamples() {
+      is_counting_samples_ = true;
+      js_and_external_sample_count_ = 0;
+  }
 
   class PlatformData;
   PlatformData* platform_data() const { return data_; }
 
  protected:
   // This method is called for each sampling period with the current
   // program counter.
   virtual void Tick(TickSample* sample) = 0;
 
  private:
   void SetActive(bool value) { NoBarrier_Store(&active_, value); }
 
   Isolate* isolate_;
   const int interval_;
   Atomic32 profiling_;
   Atomic32 active_;
   PlatformData* data_;  // Platform specific data.
-  int samples_taken_;  // Counts stack samples taken.
+  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_