I think this is probably a false positive. But from the google webmaster tools for enwiki...

"Chrome is phasing out support for the Silverlight plugin used on http://en.wikipedia.org/"

To: Webmaster of http://en.wikipedia.org/
Google systems have detected that http://en.wikipedia.org/ uses (or mentions) the Silverlight plugin. Over the next 10 months, we’ll gradually phase out support for this plugin in Chrome, which means that users browsing your site with Chrome will no longer be able to see Silverlight content. Here is the timeline:
• January 2015: all Netscape Plugin Application Programming Interface (NPAPI) plugins, including Silverlight, will be blocked by default in Chrome. Users will need to manually allow plug-ins on the site to view the content.
• April 2015: all NPAPI plugin support will be disabled by default in Chrome. Users will need to go to chrome://flags/#enable-npapi to re-enable NPAPI plugins. They will need to re-enable plugins every time they wish to view plugin content.
• September 2015: support for NPAPI plugins such as Silverlight will permanently be removed from Chrome. At that time, there will be no way for your users to access Silverlight content in Chrome.