Fix Win64 build breakage in installer

Just c4267 build suppression for a warning that just popped up.

BUG=166496
BUG=167187

TBR=grt@chroium.org
R=grt@chroium.org
Review URL: https://codereview.chromium.org/12321120

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@184500 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed