Do no delete file if they exist, even if p.is_new is True.
Do no delete file if they exist, even if p.is_new is True.

For a yet unknown reason, a chmod +x on a git svn checkout will set a 'A'
status. Will investigate separately.

R=dpranke@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6993033

git-svn-id: bd64dd6fa6f3f0ed0c0666d1018379882b742947@87903 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

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