Minor cleanup.

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 "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
@@ skipping 3787 matching lines @@
       } else {
         return Api::NewError(
             "%s expects arguments[%d] to be an Instance handle.",
             CURRENT_FUNC, i);
       }
     }
     args.SetAt((i + num_receiver), arg);
   }
 
   if (obj.IsNull() || obj.IsInstance()) {
-    Instance& instance = Instance::Handle();
+    Instance& instance = Instance::Handle(isolate);
     instance ^= obj.raw();
     const Function& function = Function::Handle(
         isolate,
         Resolver::ResolveDynamic(instance,
                                  function_name,
                                  (number_of_arguments + 1),
                                  Resolver::kIsQualified));
     args.SetAt(0, instance);
     if (function.IsNull()) {
       const Array& args_descriptor =
@@ skipping 1037 matching lines @@
   }
   {
     NoGCScope no_gc;
     RawObject* raw_obj = obj.raw();
     isolate->heap()->SetPeer(raw_obj, peer);
   }
   return Api::Success(isolate);
 }
 
 }  // namespace dart