Fix GC issue in Runtime_DebugEvaluate.

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 12596 matching lines @@
   // Add the materialized object in a with-scope to shadow the stack locals.
   context = isolate->factory()->NewWithContext(function, context, materialized);
 
   Handle<Object> receiver(frame->receiver(), isolate);
   Object* evaluate_result_object;
   { MaybeObject* maybe_result =
     DebugEvaluate(isolate, context, context_extension, receiver, source);
     if (!maybe_result->ToObject(&evaluate_result_object)) return maybe_result;
   }
 
+  Handle<Object> result(evaluate_result_object, isolate);
+
   // Write back potential changes to materialized stack locals to the stack.
   UpdateStackLocalsFromMaterializedObject(
       isolate, materialized, function, frame, inlined_jsframe_index);
 
-  return evaluate_result_object;
+  return *result;
 }
 
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_DebugEvaluateGlobal) {
   HandleScope scope(isolate);
 
   // Check the execution state and decode arguments frame and source to be
   // evaluated.
   ASSERT(args.length() == 4);
   Object* check_result;
@@ skipping 1354 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal