New version of Google Drive viewer
As part of the new Google Drive, we are updating Drive’s viewer. The new viewer is faster, cleaner and provides easier ways to connect with third-party Drive apps. It also brings a unified viewing experience across Drive content and Gmail attachments. Note that as part of this change we will remove support for adding file-level commenting of non-Google file formats. This change doesn’t impact comments in Google Docs, Sheets and Slides, and existing comments on non-Google formats will be retained and available to view.
Release track:
Rapid release and Scheduled release (rolling out gradually)
For more information:
https://support.google.com/drive/answer/2423485
Reference by: www.google.com