Chrome Version: (copy from chrome://version) 55.0.2883.87 and Canary 57.0.2947.0
OS: (e.g. Win7, OSX 10.9.5, etc...) Windows 7 Professional 64 bits. Verified on Windows 10 as well.

What steps will reproduce the problem? 
(1)Open Dev Tools (F12) and select the network section.
(2)Go to a Google site. We were able to reproduce more consistently at https://plus.google.com/collections/featured but I reproduced in drive.google.com and mail.google.com
(3)If serviceworker.js shows up in the network logs, try to Save the logs as a HAR file.

What is the expected result? 
-HAR files should be created and saved to destination specified.

What happens instead?
-HAR cannot be be saved locally.
-HAR file is created but, the file contains 0 bytes.

Able to reproduce after doing the following:

-Cleared cached and cookies.
-Removed extensions.
-Incognito mode.
-Removing user data folder.
-Able to reproduce even if user is not signed in to Chrome or the Google service.
-Able to reproduce on Windows 7/10.
-Able to reproduce on the latest version of Chrome (55.0.2883.87) and Canary(57.0.2947.0).

Please see image attachments for a reference.