Implemented GetSample like POSIX backtrace()

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index ec1941e6fd86eec42707e4d41011112961fe2109..5e0294383531a9e9259b89ac9c4e696a3043ae22 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -1415,6 +1415,14 @@ class V8_EXPORT StackFrame {
 };
 
 
+struct RegisterState {
+  RegisterState() : pc(NULL), sp(NULL), fp(NULL) {}
+  void* pc;  // Instruction pointer.
+  void* sp;  // Stack pointer.
+  void* fp;  // Frame pointer.
+};
+
+
 /**
  * A JSON Parser.
  */
@@ -4548,6 +4556,22 @@ class V8_EXPORT Isolate {
   void GetHeapStatistics(HeapStatistics* heap_statistics);
 
   /**
+   * Get a sample from the isolate.
+   * Fills out the pointer array provided in buffer
+   * up to depth elements with the stack trace pointers.
+   *
+   * \param state RegisterState which contains values of program counter (pc),
+   *              stack pointer (sp), and frame pointer (fp)
+   * \param buffer The pointer array to be filled.
+   * \return captured stack depth on success
+   *         -1 on failure.
+   * \note GetSample should only be called when the JS thread is paused or
+   *       interrupted. If that is not the case,
+   *       GetSample behaviour is undefined.
+   */
+  int GetSample(const RegisterState& state, void** buffer, unsigned int depth);
+
+  /**
    * Adjusts the amount of registered external memory. Used to give V8 an
    * indication of the amount of externally allocated memory that is kept alive
    * by JavaScript objects. V8 uses this to decide when to perform global