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

runtime/vm/dart_api_impl.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 "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
@@ skipping 1646 matching lines @@
 
 
 DART_EXPORT Dart_Handle Dart_RunLoop() {
   Thread* T = Thread::Current();
   Isolate* I = T->isolate();
   CHECK_ISOLATE_SCOPE(I);
   CHECK_CALLBACK_STATE(T);
   Monitor monitor;
   MonitorLocker ml(&monitor);
   {
-    SwitchIsolateScope switch_scope(NULL);
-
+    // The message handler run loop does not expect to have a current isolate
+    // so we exit the isolate here and enter it again after the runloop is done.
+    Thread::ExitIsolate();
     RunLoopData data;
     data.monitor = &monitor;
     data.done = false;
     I->message_handler()->Run(
         Dart::thread_pool(),
         NULL, RunLoopDone, reinterpret_cast<uword>(&data));
     while (!data.done) {
       ml.Wait();
     }
+    Thread::EnterIsolate(I);
   }
   if (I->object_store()->sticky_error() != Object::null()) {
     Dart_Handle error = Api::NewHandle(I, I->object_store()->sticky_error());
     I->object_store()->clear_sticky_error();
     return error;
   }
   if (FLAG_print_class_table) {
     HANDLESCOPE(T);
     I->class_table()->Print();
   }
@@ skipping 4396 matching lines @@
                                    ApiReallocate);
   writer.WriteFullSnapshot();
   *vm_isolate_snapshot_size = writer.VmIsolateSnapshotSize();
   *isolate_snapshot_size = writer.IsolateSnapshotSize();
   *instructions_snapshot_size = writer.InstructionsSnapshotSize();
 
   return Api::Success();
 }
 
 }  // namespace dart