message: Fix use-after-free error in summary_db_writer.cc
  BindBlobUnsafe() requires that its second argument's lifetime
  last at least until the next call to Reset() or Close().
  So that can't be used with a local variable in BindProto().
  This CL fixes this by using BindBlob() rather than BindBlobUnsafe().
diff: @@ -67,7 +67,7 @@ Status BindProto(SqliteStatement* stmt, int parameter,
  TF_RETURN_IF_ERROR(Serialize(proto, &serialized));
  string compressed;
  TF_RETURN_IF_ERROR(Compress(serialized, &compressed));
  - stmt->BindBlobUnsafe(parameter, compressed);
  + stmt->BindBlob(parameter, compressed);
  return Status::OK();
  }
  