When determining that two plugins are the same but of different versions, make sure that they share at least one mime type.
When determining that two plugins are the same but of different versions, make sure that they share at least one mime type.

BUG=43037
Review URL: http://codereview.chromium.org/1844001

git-svn-id: http://src.chromium.org/svn/trunk/src@46242 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: e7206ba88e0144636ad0ac2ed64c2dfc4013ab04
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