Since the Plugins page has been removed in upcoming Chrome 57, you may find it difficult to manage PPAPI-based Flash and built-in PDF Viewer plugins, if you don’t know, they’ve been moved to content settings. If you want to disable/enable the Chrome PDF Viewer from version 57 onwards, you need to follow the below steps.
Disabling or enabling Chrome PDF Viewer in Chrome 57+
1. Click on Chrome menu, select Settings
2. Scroll down and click on Advanced
3. Under Privacy & Security, click on Content Settings,
4. Click on PDF Documents,
- To disable Chrome PDF Viewer, turn on ‘Download PDF files instead of automatically opening them in Chrome’ Setting,
- To enable PDF Viewer, you need to turn off the above mentioned setting.
Done! Chrome Internal PDF Viewer will be enabled/disabled as per the setting chosen by you.
Note: Chrome blocks Flash by default. You can allow sites to run Flash or manually add sites that can run Flash by visiting the Flash section in Content Settings.
Update: Added screenshot of Material Settings page of Chrome version 60 above.