linux: hide more warnings in third-party code
linux: hide more warnings in third-party code

I was confused why we were getting warnings related to format
strings, since they are off in gcc unless you use -Wall or
explicitly enable it, but it turns out that the man page calls
out that it is specially enabled on Ubuntu.

Review URL: http://codereview.chromium.org/6469002

git-svn-id: http://src.chromium.org/svn/trunk/src@74351 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 05bd7382b9ea41bd7177e905b56e3aeab015de6f
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