gn format: penalty-based line breaking WIP XXX

tools/gn/parser.cc

Index: tools/gn/parser.cc
diff --git a/tools/gn/parser.cc b/tools/gn/parser.cc
index 38f7abbf2dece58d5957e4378e98e7cf08ff4cfe..68be911843f6b55e24bc0d0285244a9a4664bb50 100644
--- a/tools/gn/parser.cc
+++ b/tools/gn/parser.cc
@@ -289,15 +289,18 @@ scoped_ptr<ParseNode> Parser::IdentifierOrCall(scoped_ptr<ParseNode> left,
   bool has_arg = false;
   if (LookAhead(Token::LEFT_PAREN)) {
     Token start_token = Consume();
+    list->set_begin_token(start_token);
     // Parsing a function call.
     has_arg = true;
-    if (Match(Token::RIGHT_PAREN)) {
+    if (LookAhead(Token::RIGHT_PAREN)) {
       // Nothing, just an empty call.
+      list->set_end(make_scoped_ptr(new EndNode(Consume())));
     } else {
       list = ParseList(start_token, Token::RIGHT_PAREN, false);
       if (has_error())
         return scoped_ptr<ParseNode>();
-      Consume(Token::RIGHT_PAREN, "Expected ')' after call");
+      list->set_end(make_scoped_ptr(
+          new EndNode(Consume(Token::RIGHT_PAREN, "Expected ')' after call"))));
     }
     // Optionally with a scope.
     if (LookAhead(Token::LEFT_BRACE)) {