Fix test-serialize.

test/cctest/test-serialize.cc

 // Copyright 2007-2010 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 275 matching lines @@
   virtual ~FileByteSink() {
     if (fp_ != NULL) {
       fclose(fp_);
     }
   }
   virtual void Put(int byte, const char* description) {
     if (fp_ != NULL) {
       fputc(byte, fp_);
     }
   }
+  virtual int Position() {
+    return ftell(fp_);
+  }
   void WriteSpaceUsed(
       int new_space_used,
       int pointer_space_used,
       int data_space_used,
       int code_space_used,
       int map_space_used,
       int cell_space_used,
       int large_space_used);
 
  private:
@@ skipping 199 matching lines @@
 TEST(TestThatAlwaysFails) {
   bool ArtificialFailure = false;
   CHECK(ArtificialFailure);
 }
 
 
 DEPENDENT_TEST(DependentTestThatAlwaysFails, TestThatAlwaysSucceeds) {
   bool ArtificialFailure2 = false;
   CHECK(ArtificialFailure2);
 }