gn: More helpful default args file

tools/gn/command_args.cc

Index: tools/gn/command_args.cc
diff --git a/tools/gn/command_args.cc b/tools/gn/command_args.cc
index 8098ea18f9e51f164ad6f4ab5ceb53c4981dd306..efdb267d0dd9968d6056e90eb3a644dffcbea4dd 100644
--- a/tools/gn/command_args.cc
+++ b/tools/gn/command_args.cc
@@ -243,8 +243,9 @@ int EditArgsFile(const std::string& build_dir) {
     if (!base::PathExists(arg_file)) {
       std::string argfile_default_contents =
           "# Build arguments go here. Examples:\n"
-          "#   enable_doom_melon = true\n"
-          "#   crazy_something = \"absolutely\"\n";
+          "#   is_component_build = true\n"
+          "#   is_debug = false\n"
+          "# See \"gn args --list\" for available build arguments.\n";

[scottmg, 2014/12/12 23:29:20]

I think this has to be "gn args out/gn --list".

[mdempsky, 2014/12/12 23:41:37]

I changed it to

  # See "gn args <dir_name> --list" for available build arguments.

to match "gn help args".

We could theoretically interpolate |build_dir| here, but I figure this is
simpler and avoids issues if a user specifies an absolute path (could result in
a really long command) or renames the build directory (the example file won't be
updated, and embedded directory name would become stale).

 #if defined(OS_WIN)
       // Use Windows lineendings for this file since it will often open in
       // Notepad which can't handle Unix ones.