1. Get rid of SwitchIsolateScope as it is not clear when this should be used and there is also a bu…

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 "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
@@ skipping 1436 matching lines @@
     StartIsolateScope start_scope(isolate);
     ASSERT(thread->isolate() == isolate);
     StackZone zone(thread);
     HandleScope handle_scope(thread);
     const Error& error = Error::Handle(isolate->object_store()->sticky_error());
     if (!error.IsNull() && !error.IsUnwindError()) {
       OS::PrintErr("in ShutdownIsolate: %s\n", error.ToErrorCString());
     }
     Dart::RunShutdownCallback();
   }
-  {
-    // Shut the isolate down.
-    SwitchIsolateScope switch_scope(isolate);
-    Dart::ShutdownIsolate();
-  }
+  // Shut the isolate down.
+  Dart::ShutdownIsolate(isolate);
 }
 
 
 void Isolate::Run() {
   message_handler()->Run(Dart::thread_pool(),
                          RunIsolate,
                          ShutdownIsolate,
                          reinterpret_cast<uword>(this));
 }
 
@@ skipping 185 matching lines @@
     // The VM isolate keeps all objects marked.
     heap_->Verify(this == Dart::vm_isolate() ? kRequireMarked : kForbidMarked);
   }
 #endif  // DEBUG
 
   // Wait until all background compilation has finished.
   BackgroundCompiler::Stop(background_compiler_);
 
   Thread* thread = Thread::Current();
 
+  // Don't allow anymore dart code to execution on this isolate.
+  ClearStackLimit();
+
   // First, perform higher-level cleanup that may need to allocate.
   {
     // Ensure we have a zone and handle scope so that we can call VM functions.
     StackZone stack_zone(thread);
     HandleScope handle_scope(thread);
 
     // Write out the coverage data if collection has been enabled.
     if ((this != Dart::vm_isolate()) &&
         !ServiceIsolate::IsServiceIsolateDescendant(this)) {
       CodeCoverage::Write(thread);
@@ skipping 930 matching lines @@
 }
 
 
 RawInstance* IsolateSpawnState::BuildMessage(Thread* thread) {
   return DeserializeObject(thread,
                            serialized_message_, serialized_message_len_);
 }
 
 
 }  // namespace dart