Introduce JIT code events dispatcher for the isolate.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 035a626acd2eff1ba4439ae8b322a2fe3ba93af6..6578ce16fc138b294f6bf90676c469b2079141f6 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1869,6 +1869,7 @@ Isolate::Isolate(bool enable_serializer)
       is_tail_call_elimination_enabled_(true),
       cpu_profiler_(NULL),
       heap_profiler_(NULL),
+      code_event_dispatcher_(new CodeEventDispatcher()),
       function_entry_hook_(NULL),
       deferred_handles_head_(NULL),
       optimizing_compile_dispatcher_(NULL),
@@ -2026,6 +2027,8 @@ void Isolate::Deinit() {
   delete cpu_profiler_;
   cpu_profiler_ = NULL;
 
+  code_event_dispatcher_.reset();

[Yang, 2016/06/14 13:38:12]

Is there an advantage for using unique_ptr over using a raw pointer that we have
to delete here?

[alph, 2016/06/14 16:38:20]

It better depicts ownership semantics used here, and is more leakproof.

+
   delete root_index_map_;
   root_index_map_ = NULL;