Add temporary FilterType default branches in preparation of FilterTypeSaturatingBrightness

To prevent compile warnings (treated as errors) when the new FilterType lands in WK, this patch
adds temporary default branches to ParamTraits<WebKit::WebFilterOperation>::*.

R=senorblanco@google.com

BUG=

Review URL: https://codereview.chromium.org/12209071

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181742 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed