Revert "Fix VM not accepting static methods for Isolate.spawn."

runtime/lib/isolate.cc

 // Copyright (c) 2012, 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 "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 202 matching lines @@
   return port.raw();
 }
 
 
 DEFINE_NATIVE_ENTRY(Isolate_spawnFunction, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, closure, arguments->NativeArgAt(0));
   bool throw_exception = false;
   Function& func = Function::Handle();
   if (closure.IsClosure()) {
     func = Closure::function(closure);
-    if (!(func.IsImplicitClosureFunction() && func.is_static())) {
+    const Class& cls = Class::Handle(func.Owner());
+    if (!func.IsClosureFunction() || !func.is_static() || !cls.IsTopLevel()) {
       throw_exception = true;
     }
   } else {
     throw_exception = true;
   }
   if (throw_exception) {
     const String& msg = String::Handle(String::New(
-        "Isolate.spawn expects to be passed a static or top-level function"));
+        "Isolate.spawn expects to be passed a top-level function"));
     Exceptions::ThrowArgumentError(msg);
   }
 
 #if defined(DEBUG)
   Context& ctx = Context::Handle();
   ctx = Closure::context(closure);
   ASSERT(ctx.num_variables() == 0);
 #endif
 
   return Spawn(arguments, new IsolateSpawnState(func));
@@ skipping 26 matching lines @@
 
   // The control port is being accessed as a regular port from Dart code. This
   // is most likely due to the _startIsolate code in dart:isolate. Account for
   // this by increasing the number of open control ports.
   isolate->message_handler()->increment_control_ports();
 
   return port.raw();
 }
 
 }  // namespace dart