Use dot_for_symbol.

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index c2fd015491bd0e117b1d0bc86ac87f8601f1be11..129bd95466520ef87de7bc6e7c5ac61234cd9f48 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -2843,9 +2843,8 @@ Statement* Parser::ParseForStatement(ZoneStringList* labels, bool* ok) {
         // TODO(keuchel): Move the temporary variable to the block scope, after
         // implementing stack allocated block scoped variables.
         Factory* heap_factory = isolate()->factory();
-        Handle<String> dot =
-            heap_factory->NewStringFromAscii(CStrVector(".for."));
-        Handle<String> tempstr = heap_factory->NewConsString(dot, name);
+        Handle<String> tempstr =
+            heap_factory->NewConsString(heap_factory->dot_for_symbol(), name);
         Handle<String> tempname = heap_factory->LookupSymbol(tempstr);
         Variable* temp = top_scope_->DeclarationScope()->NewTemporary(tempname);
         VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);