title: Where is "Chrome PDF viewer" extension "mhjfbmdgcfjbbpaeojofohoefgiehjai" located?
body: <p>How can I find the folder for chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai (the hidden "Chrome PDF viewer")?</p>
  
  <p>I need to access these files and change its JavaScript to send me a message before printing a PDF.</p>