Expose TickSample and its APIs in v8-profiler.h

src/profiler/circular-queue.h

Index: src/profiler/circular-queue.h
diff --git a/src/profiler/circular-queue.h b/src/profiler/circular-queue.h
index 272843bb2df120480638082553988d6fc35704a9..e4d12d5e7998245d0d2fa65030a0a4e9363baf0a 100644
--- a/src/profiler/circular-queue.h
+++ b/src/profiler/circular-queue.h
@@ -31,6 +31,8 @@ class SamplingCircularQueue {
   // Notifies the queue that the producer has complete writing data into the
   // memory returned by StartEnqueue and it can be passed to the consumer.
   void FinishEnqueue();
+  // Returns the current memory for enqueue.
+  T* CurrentEnqueue();
 
   // Executed on the consumer (analyzer) thread.
   // Retrieves, but does not remove, the head of this queue, returning NULL