Invalidate cached render text for match contents when the omnibox result view is invalidated

When selection state of a result view changes, the cached render text should be
reset and rendered again.

BUG=346607

Review URL: https://codereview.chromium.org/176923011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253526 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253526