Thanks for the issue..

As per original comment, able to reproduce the issue on reported chrome 70.0.3538.77, chrome 72.0.3610.0 and m-60 using Ubuntu 17.10. Attaching screenshot for reference.
Steps:
-----
1. Launched reported chrome
2. Opened given link and clicked on ctrl + s to save the page 
3. Opened text file on text editor 
As we have observed that text displayed in the browser and in the text editor not matched

Observations: 
1. From M-60 to M-61 observed > both chrome browser and Text editor(same as latest chrome) seen different as per attached screenshots (see 61.0.3113.0 screenshot)
2.From  M-62 to M-72 observed > chrome browser and Text editor are different as per attached screenshots

@Reporter: Could you please check the attached screenshots and confirm the issue. 

Thanks..!

Deleted: 905521-61.0.3113.0.png 213 KB

	905521-61.0.3113.0.png 213 KB View Download

Deleted: 905521--M62 to M-72.png 129 KB

	905521--M62 to M-72.png 129 KB View Download

Deleted: 905521-Text Editor.png 132 KB

	905521-Text Editor.png 132 KB View Download

yep, reproduced, I think it was downloaded with the same encoding too, you can check by running this command in the terminal:  file ara.bigrams.txt
it should output: 
ara.bigrams.txt: UTF-8 Unicode text
not 
ara.bigrams.txt: ISO-8859 text

it looks like on versions <=61, it didn't render properly (is it an issue with auto-encoding detection?).

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

As per comment #4, Able to reproduce the issue on reported chrome version 70.0.3538.77 also on latest chrome 72.0.3611.0 using Mac 10.14.0, Ubuntu 17.10 and Windows 10.  
 
Same behavior is seen on M60(60.0.3112.113) hence considering it as non-regression and marking it as Untriaged. Removing Needs-Bisect label to it.

Thanks!