<http://bugs.webkit.org/show_bug.cgi?id=18208>

        We now keep track of all the plugin paths found each time refresh() is
        called. We'll only instantiate PluginPackages if there are new paths
        or paths with changed timestamps since the last time refresh() was
        called.

        Reviewed by Darin Adler and Anders Carlsson.

        * plugins/PluginDatabase.cpp:
        (WebCore::PluginDatabase::refresh):
          - Only instantiate PluginPackages if there is a new path or a path
            with a changed timestamp since we last ran refresh().
          - Cache the set of plugin paths found and their timestamps for the
            next call to refresh().
          - Only re-register MIME types if our set of plugins changed.
        * plugins/PluginDatabase.h: Added a new member to cache plugin paths
        and their timestamps.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@31466 268f45cc-cd09-0410-ab3c-d52691b4dbfc