Add libwww-perl to the list of installed packages.
Add libwww-perl to the list of installed packages.

There are two WebKit layout tests that try to use the HTTP::Date
perl module.  This seems to be part of ubuntu-desktop, but in my chroot,
I needed to manually install this package.

Review URL: http://codereview.chromium.org/7237053

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@91899 0039d316-1c4b-4281-b951-d872f2087c98

adobe/chromium,adobe/chromium,gavinp/chromium,adobe/chromium,gavinp/chromium,ropik/chromium,adobe/chromium,gavinp/chromium,ropik/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,ropik/chromium,gavinp/chromium,ropik/chromium,yitian134/chromium,yitian134/chromium,yitian134/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,ropik/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,ropik/chromium,gavinp/chromium,adobe/chromium,gavinp/chromium