add a -n/--dry-run to the new fetch command in depot_tools
add a -n/--dry-run to the new fetch command in depot_tools

This is done as a hack since we don't really have real option parsing :(.

R=iannucci@chromium.org, agable@chromium.org, maruel@chromium.org

Review URL: https://codereview.chromium.org/13586004

git-svn-id: bd64dd6fa6f3f0ed0c0666d1018379882b742947@192154 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

svn2github/chromium-depot-tools,svn2github/chromium-depot-tools,svn2github/chromium-depot-tools