Add unistd.h include in a file using geteuid().

sql/sqlite_features_unittest.cc

Index: sql/sqlite_features_unittest.cc
diff --git a/sql/sqlite_features_unittest.cc b/sql/sqlite_features_unittest.cc
index 4fc730c2b8120cb093ed2cb7f84aa4583e127070..e30d0a49880dbc30c19d51c357df69032b6bf11e 100644
--- a/sql/sqlite_features_unittest.cc
+++ b/sql/sqlite_features_unittest.cc
@@ -46,10 +46,6 @@ class SQLiteFeaturesTest : public testing::Test {
 
   sql::Connection& db() { return db_; }
 
-  int sqlite_error() const {
-    return error_;
-  }
-
  private:
   base::ScopedTempDir temp_dir_;
   sql::Connection db_;