Do not go to slow mode and back to fast in initializer blocks.

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 5014 matching lines @@
 
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ToFastProperties) {
   ASSERT(args.length() == 1);
   Object* object = args[0];
   return (object->IsJSObject() && !object->IsGlobalObject())
       ? JSObject::cast(object)->TransformToFastProperties(0)
       : object;
 }
 
 
-RUNTIME_FUNCTION(MaybeObject*, Runtime_ToSlowProperties) {
-  ASSERT(args.length() == 1);
-  Object* obj = args[0];
-  return (obj->IsJSObject() && !obj->IsJSGlobalProxy())
-      ? JSObject::cast(obj)->NormalizeProperties(CLEAR_INOBJECT_PROPERTIES, 0)
-      : obj;
-}
-
-
 RUNTIME_FUNCTION(MaybeObject*, Runtime_ToBool) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
   return args[0]->ToBoolean();
 }
 
 
 // Returns the type string of a value; see ECMA-262, 11.4.3 (p 47).
 // Possible optimizations: put the type string into the oddballs.
@@ skipping 8230 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