Not able to set width using ColGroup in the table.

We ignored a col / colgroup that were not present at the start of the table
for the purpose of layout.

Other browsers would take into account the col / colgroup anywhere in the table
so this change makes us match them.

The 2 new baselines are progressions (as in we match other browsers)

R=jchaffraix@chromium.org
BUG=305169

Review URL: https://codereview.chromium.org/26360003

git-svn-id: svn://svn.chromium.org/blink/trunk@159442 bbb929c8-8fbe-4397-9dbb-9b2b20218538