Take instrumentation overhead into account when plotting.

src/log-utils.cc

Index: src/log-utils.cc
diff --git a/src/log-utils.cc b/src/log-utils.cc
index 246f6851359ebc8ece402d60fad6157fd089df9b..d8d92cbe211607f03e2a6f131f6f2f481b47f023 100644
--- a/src/log-utils.cc
+++ b/src/log-utils.cc
@@ -67,7 +67,7 @@ void Log::Initialize() {
     FLAG_log_suspect = true;
     FLAG_log_handles = true;
     FLAG_log_regexp = true;
-    FLAG_log_timer_events = true;
+    FLAG_log_internal_timer_events = true;
   }
 
   // --prof implies --log-code.
@@ -82,7 +82,7 @@ void Log::Initialize() {
   bool open_log_file = FLAG_log || FLAG_log_runtime || FLAG_log_api
       || FLAG_log_code || FLAG_log_gc || FLAG_log_handles || FLAG_log_suspect
       || FLAG_log_regexp || FLAG_log_state_changes || FLAG_ll_prof
-      || FLAG_log_timer_events;
+      || FLAG_log_internal_timer_events;
 
   // If we're logging anything, we need to open the log file.
   if (open_log_file) {