Remove work-around for old filesystem:-bug
Remove work-around for old filesystem:-bug

https://crbug.com/362061 was fixed in Chrome 36, and the lowest
supported Chrome version in the extension is Chrome 49, so the
work-around for a filesystem:-bug in chromecom can be removed.

caremerge/pdf.js,xavier114fch/pdf.js,xavier114fch/pdf.js,mainegreen/pdf.js,Snuffleupagus/pdf.js,macroplant/pdf.js,mozilla/pdf.js,showpad/mozilla-pdf.js,Rob--W/pdf.js,nawawi/pdf.js,mozilla/pdf.js,Rob--W/pdf.js,timvandermeij/pdf.js,Shoobx/pdf.js,nawawi/pdf.js,nawawi/pdf.js,Snuffleupagus/pdf.js,Shoobx/pdf.js,Snuffleupagus/pdf.js,mukulmishra18/pdf.js,Shoobx/pdf.js,showpad/mozilla-pdf.js,timvandermeij/pdf.js,macroplant/pdf.js,mozilla/pdf.js,timvandermeij/pdf.js,mukulmishra18/pdf.js,mainegreen/pdf.js,macroplant/pdf.js,showpad/mozilla-pdf.js,caremerge/pdf.js