Add support for allowing an embedder to get the V8 profile timer event logs.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index dd8f2685bc37115638f5332ddbefd42a79c16cea..c5eeceaa33e576c04fe5796bd038217ed6575165 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -3805,6 +3805,9 @@ typedef void (*FatalErrorCallback)(const char* location, const char* message);
 
 typedef void (*MessageCallback)(Handle<Message> message, Handle<Value> error);
 
+// --- Tracing ---
+
+typedef void (*LogEventCallback)(const char* name, int event);
 
 /**
  * Create new error objects by calling the corresponding error object
@@ -4191,6 +4194,11 @@ class V8_EXPORT Isolate {
    */
   void RequestGarbageCollectionForTesting(GarbageCollectionType type);
 
+  /**
+   * Set the callback to invoke for logging event.
+   */
+  void SetEventLogger(LogEventCallback that);
+
  private:
   Isolate();
   Isolate(const Isolate&);