Add a dry-run option to gyp_skia.

There are times when I want to do some low-level fiddling with the gyp
command. It's nice to start with whatever the 'default' is, and it's also
nice to peek behind the curtain to see what's going on. To this end,
a '--dry-run' in the argument list will spit out the command to run,
rather than running the command.

R=epoger@google.com

Review URL: https://codereview.chromium.org/278893002

git-svn-id: http://skia.googlecode.com/svn/trunk@14674 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed