Update VM service to new isolate API

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index d8ab9a53852f0d8d4789fda623e5a59226beacad..50cf69fa22385cb3406fb5c9d6c6e9487c224d18 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -279,6 +279,7 @@ Isolate::Isolate()
       name_(NULL),
       start_time_(OS::GetCurrentTimeMicros()),
       main_port_(0),
+      service_port_(0),
       heap_(NULL),
       object_store_(NULL),
       top_context_(Context::null()),
@@ -385,6 +386,7 @@ Isolate* Isolate::Init(const char* name_prefix) {
   // main thread.
   result->SetStackLimitFromCurrentTOS(reinterpret_cast<uword>(&result));
   result->set_main_port(PortMap::CreatePort(result->message_handler()));
+  result->set_service_port(PortMap::CreatePort(result->message_handler()));

[Ivan Posva, 2013/10/25 00:30:27]

What is this service port used for? How does the VM account for the additional
open port when determining to terminate an isolate?

[Cutch, 2013/10/25 01:21:57]

(Florian is closing the main port from Dart code as part of his port/cleanup,
this was stopping the VM service from communicating with the isolate).

Using a separate port allows for Dart code to close the main port but still have
service messages delivered to isolates. 

The service port is only ever used as a SendPort (vm service sends OOB messages
over the SendPort) so it does not increment the live port count (except
momentarily when a service message is in flight and we allocate a ReceivePort)
and does not interfere with isolate shutdown.

   result->BuildName(name_prefix);
 
   result->debugger_ = new Debugger();