diff --git a/src/profiler/sampler.h b/src/profiler/sampler.h
new file mode 100644
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+++ b/src/profiler/sampler.h
@@ -0,0 +1,136 @@
+// Copyright 2013 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.
+
+#ifndef V8_PROFILER_SAMPLER_H_
+#define V8_PROFILER_SAMPLER_H_
+
+#include "include/v8.h"
+
+#include "src/base/atomicops.h"
+#include "src/base/platform/time.h"
+#include "src/frames.h"
+#include "src/globals.h"
+
+namespace v8 {
+namespace internal {
+
+class Isolate;
+
+// ----------------------------------------------------------------------------
+// Sampler
+//
+// A sampler periodically samples the state of the VM and optionally
+// (if used for profiling) the program counter and stack pointer for
+// the thread that created it.
+
+// TickSample captures the information collected for each sample.
+struct TickSample {
+  // Internal profiling (with --prof + tools/$OS-tick-processor) wants to
+  // include the runtime function we're calling. Externally exposed tick
+  // samples don't care.
+  enum RecordCEntryFrame { kIncludeCEntryFrame, kSkipCEntryFrame };
+
+  TickSample()
+      : state(OTHER),
+        pc(NULL),
+        external_callback(NULL),
+        frames_count(0),
+        has_external_callback(false),
+        top_frame_type(StackFrame::NONE) {}
+  void Init(Isolate* isolate, const v8::RegisterState& state,
+            RecordCEntryFrame record_c_entry_frame);
+  static void GetStackSample(Isolate* isolate, const v8::RegisterState& state,
+                             RecordCEntryFrame record_c_entry_frame,
+                             void** frames, size_t frames_limit,
+                             v8::SampleInfo* sample_info);
+  StateTag state;  // The state of the VM.
+  Address pc;      // Instruction pointer.
+  union {
+    Address tos;   // Top stack value (*sp).
+    Address external_callback;
+  };
+  static const unsigned kMaxFramesCountLog2 = 8;
+  static const unsigned kMaxFramesCount = (1 << kMaxFramesCountLog2) - 1;
+  Address stack[kMaxFramesCount];  // Call stack.
+  base::TimeTicks timestamp;
+  unsigned frames_count : kMaxFramesCountLog2;  // Number of captured frames.
+  bool has_external_callback : 1;
+  StackFrame::Type top_frame_type : 4;
+};
+
+class Sampler {
+ public:
+  // Initializes the Sampler support. Called once at VM startup.
+  static void SetUp();
+  static void TearDown();
+
+  // Initialize sampler.
+  Sampler(Isolate* isolate, int interval);
+  virtual ~Sampler();
+
+  Isolate* isolate() const { return isolate_; }
+  int interval() const { return interval_; }
+
+  // Performs stack sampling.
+  void SampleStack(const v8::RegisterState& regs);
+
+  // Start and stop sampler.
+  void Start();
+  void Stop();
+
+  // Whether the sampling thread should use this Sampler for CPU profiling?
+  bool IsProfiling() const {
+    return base::NoBarrier_Load(&profiling_) > 0 &&
+        !base::NoBarrier_Load(&has_processing_thread_);
+  }
+  void IncreaseProfilingDepth();
+  void DecreaseProfilingDepth();
+
+  // Whether the sampler is running (that is, consumes resources).
+  bool IsActive() const { return base::NoBarrier_Load(&active_); }
+
+  void DoSample();
+  // If true next sample must be initiated on the profiler event processor
+  // thread right after latest sample is processed.
+  void SetHasProcessingThread(bool value) {
+    base::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;
+      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) { base::NoBarrier_Store(&active_, value); }
+
+  Isolate* isolate_;
+  const int interval_;
+  base::Atomic32 profiling_;
+  base::Atomic32 has_processing_thread_;
+  base::Atomic32 active_;
+  PlatformData* data_;  // Platform specific data.
+  bool is_counting_samples_;
+  // Counts stack samples taken in JS VM state.
+  unsigned js_and_external_sample_count_;
+  DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
+};
+
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_PROFILER_SAMPLER_H_