[serializer] do not cache resource data pointer for native source.

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 2288 matching lines @@
       }
       Map* map = Map::cast(obj);
       map->SetConstructorFunctionIndex(Context::STRING_FUNCTION_INDEX);
       // Mark cons string maps as unstable, because their objects can change
       // maps during GC.
       if (StringShape(entry.type).IsCons()) map->mark_unstable();
       roots_[entry.index] = map;
     }
 
     {  // Create a separate external one byte string map for native sources.
-      AllocationResult allocation = AllocateMap(EXTERNAL_ONE_BYTE_STRING_TYPE,
-                                                ExternalOneByteString::kSize);
+      AllocationResult allocation =
+          AllocateMap(SHORT_EXTERNAL_ONE_BYTE_STRING_TYPE,
+                      ExternalOneByteString::kShortSize);
       if (!allocation.To(&obj)) return false;
       Map* map = Map::cast(obj);
       map->SetConstructorFunctionIndex(Context::STRING_FUNCTION_INDEX);
       set_native_source_string_map(map);
     }
 
     ALLOCATE_VARSIZE_MAP(FIXED_DOUBLE_ARRAY_TYPE, fixed_double_array)
     fixed_double_array_map()->set_elements_kind(FAST_HOLEY_DOUBLE_ELEMENTS);
     ALLOCATE_VARSIZE_MAP(BYTE_ARRAY_TYPE, byte_array)
     ALLOCATE_VARSIZE_MAP(BYTECODE_ARRAY_TYPE, bytecode_array)
@@ skipping 4039 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8