Add more timing information in the VM to track time spent is dart code Vs native code.

runtime/vm/timer.h

Index: runtime/vm/timer.h
===================================================================
--- runtime/vm/timer.h	(revision 32801)
+++ runtime/vm/timer.h	(working copy)
@@ -83,6 +83,7 @@
   V(time_compilation, "Function compilation")                                  \
   V(time_bootstrap, "Bootstrap of core classes")                               \
   V(time_dart_execution, "Dart execution")                                     \
+  V(time_native_execution, "Native code execution")                            \
   V(time_total_runtime, "Total runtime for isolate")                           \
 
 // Maintains a list of timers per isolate.
@@ -98,6 +99,7 @@
 #undef TIMER_FIELD_ACCESSOR
 
   void ReportTimers();
+  void ReportTimerState(const char* prefix);
 
   void PrintTimersToJSONProperty(JSONObject* jsobj);
 
@@ -110,52 +112,15 @@
 };
 
 // Timer Usage.
-#define START_TIMER(name)                                                      \
-  Isolate::Current()->timer_list().name().Start();
+#define START_TIMER(isolate, name)                                             \
+  isolate->timer_list().name().Start();
 
-#define STOP_TIMER(name)                                                       \
-  Isolate::Current()->timer_list().name().Stop();
+#define STOP_TIMER(isolate, name)                                              \
+  isolate->timer_list().name().Stop();
 
-// The class TimerScope is used to start and stop a timer within a scope.
-// It is used as follows:
-// {
-//   TIMERSCOPE(name_of_timer);
-//   ....
-//   .....
-//   code that needs to be timed.
-//   ....
-// }
-class TimerScope : public StackResource {
- public:
-  TimerScope(bool flag, Timer* timer, BaseIsolate* isolate = NULL)
-      : StackResource(isolate), flag_(flag), nested_(false), timer_(timer) {
-    if (flag_) {
-      if (!timer_->running()) {
-        timer_->Start();
-      } else {
-        nested_ = true;
-      }
-    }
-  }
-  ~TimerScope() {
-    if (flag_) {
-      if (!nested_) {
-        timer_->Stop();
-      }
-    }
-  }
+#define TIMER_STATE(isolate, prefix)                                           \
+  isolate->timer_list().ReportTimerState(prefix);
 
- private:
-  bool flag_;
-  bool nested_;
-  Timer* timer_;
-  DISALLOW_COPY_AND_ASSIGN(TimerScope);
-};
-
-#define TIMERSCOPE(name)                                                       \
-  TimerScope vm_internal_timer_(true,                                          \
-                                &(Isolate::Current()->timer_list().name()))
-
 }  // namespace dart
 
 #endif  // VM_TIMER_H_