Tweak CSS to give the client scrollbars.
Tweak CSS to give the client scrollbars.

The horizontal scrollbar is attached to the plugin, not to the page,
so it's only visible if the page is scrolled to the bottom.

BUG=74681
TEST=none

Review URL: http://codereview.chromium.org/6628080

git-svn-id: http://src.chromium.org/svn/trunk/src@77304 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 6c0dd9283acf42dfbeee2e9569bb09fdd80ebbb0
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