[heap] Remove dead counters and move regexp code counter to Isolate

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index afe09ba08bc3b14865d241898d2311b5f38b4998..b10f0b42ab62fc18c77a1933585f75d4657203b4 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -2241,7 +2241,8 @@ Isolate::Isolate(bool enable_serializer)
       use_counter_callback_(NULL),
       basic_block_profiler_(NULL),
       cancelable_task_manager_(new CancelableTaskManager()),
-      abort_on_uncaught_exception_callback_(NULL) {
+      abort_on_uncaught_exception_callback_(NULL),
+      total_regexp_code_generated_(0) {
   {
     base::LockGuard<base::Mutex> lock_guard(thread_data_table_mutex_.Pointer());
     CHECK(thread_data_table_);