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

runtime/vm/isolate.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
 #include "lib/mirrors.h"
@@ skipping 86 matching lines @@
     // Allow the embedder to handle message notification.
     (*callback)(Api::CastIsolate(isolate_));
   }
 }
 
 
 bool IsolateMessageHandler::HandleMessage(Message* message) {
   StartIsolateScope start_scope(isolate_);
   StackZone zone(isolate_);
   HandleScope handle_scope(isolate_);
-  // TODO(turnidge): Rework collection total dart execution.  This can
-  // overcount when other things (gc, compilation) are active.
-  TIMERSCOPE(time_dart_execution);
 
   // If the message is in band we lookup the receive port to dispatch to.  If
   // the receive port is closed, we drop the message without deserializing it.
   Object& receive_port = Object::Handle();
   if (!message->IsOOB()) {
     receive_port = DartLibraryCalls::LookupReceivePort(message->dest_port());
     if (receive_port.IsError()) {
       return ProcessUnhandledException(Object::null_instance(),
                                        Error::Cast(receive_port));
     }
@@ skipping 128 matching lines @@
     if ((exception != isolate_->object_store()->out_of_memory()) &&
         (exception != isolate_->object_store()->stack_overflow())) {
       if (UnhandledExceptionCallbackHandler(message, error)) {
         return true;
       }
     }
   }
 
   // Invoke the isolate's unhandled exception callback if there is one.
   if (Isolate::UnhandledExceptionCallback() != NULL) {
+    VmToNativeTimerScope timer(Isolate::Current());
     Dart_EnterScope();
     Dart_Handle error = Api::NewHandle(isolate_, result.raw());
     (Isolate::UnhandledExceptionCallback())(error);
     Dart_ExitScope();
   }
 
   isolate_->object_store()->set_sticky_error(result);
   return false;
 }
 
@@ skipping 783 matching lines @@
   return func.raw();
 }
 
 
 void IsolateSpawnState::Cleanup() {
   SwitchIsolateScope switch_scope(isolate());
   Dart::ShutdownIsolate();
 }
 
 }  // namespace dart