Fix Chromium issue 47824.

src/handles.cc

 // Copyright 2009 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 179 matching lines @@
 
 void TransformToFastProperties(Handle<JSObject> object,
                                int unused_property_fields) {
   CALL_HEAP_FUNCTION_VOID(
       object->TransformToFastProperties(unused_property_fields));
 }
 
 
 void FlattenString(Handle<String> string) {
   CALL_HEAP_FUNCTION_VOID(string->TryFlatten());
-  ASSERT(string->IsFlat());
 }
 
 
+Handle<String> FlattenGetString(Handle<String> string) {
+  Handle<String> result;
+  CALL_AND_RETRY(string->TryFlatten(),
+                 { result = Handle<String>(String::cast(__object__));
+                   break; },
+                 return Handle<String>());
+  ASSERT(string->IsFlat());
+  return result;
+}
+
+
 Handle<Object> SetPrototype(Handle<JSFunction> function,
                             Handle<Object> prototype) {
   ASSERT(function->should_have_prototype());
   CALL_HEAP_FUNCTION(Accessors::FunctionSetPrototype(*function,
                                                      *prototype,
                                                      NULL),
                      Object);
 }
 
 
@@ skipping 588 matching lines @@
 
 OptimizedObjectForAddingMultipleProperties::
 ~OptimizedObjectForAddingMultipleProperties() {
   // Reoptimize the object to allow fast property access.
   if (has_been_transformed_) {
     TransformToFastProperties(object_, unused_property_fields_);
   }
 }
 
 } }  // namespace v8::internal