Add benchmark output to compiler stats.

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 0c992e107299e90b5e28aabe6b28ebb5fd0192bd..5100259d3275a555f4dd6b2e0d1fb9f3297be182 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -842,9 +842,12 @@ Isolate* Isolate::Init(const char* name_prefix,
                 "\tisolate:    %s\n", result->name());
     }
   }
-  if (FLAG_compiler_stats) {
-    result->compiler_stats_ = new CompilerStats(result);
+
+  result->compiler_stats_ = new CompilerStats(result);
+  if (FLAG_compiler_benchmark) {
+    result->compiler_stats_->EnableBenchmark();
   }
+
   ObjectIdRing::Init(result);
   // Add to isolate list.
   AddIsolateTolist(result);
@@ -1506,7 +1509,7 @@ void Isolate::Shutdown() {
     HandleScope handle_scope(thread);
     NoSafepointScope no_safepoint_scope;
 
-    if (compiler_stats_ != NULL) {
+    if (FLAG_compiler_stats) {
       OS::Print("%s", compiler_stats()->PrintToZone());
     }