Disk Cache: Make sure that file descriptors are valid before calling close().
Disk Cache: Make sure that file descriptors are valid before calling close().

BUG=71399
TEST=none

Review URL: http://codereview.chromium.org/6490007

git-svn-id: http://src.chromium.org/svn/trunk/src@74486 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: cb709319879eafbaf98e987ef7b0a6691e541114
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser