Unreadable font on Gmail since recent updates in Chromium

I had a similar issue with Google Chrome and Outlook.com (I know different site & slightly different browser, but the code should help). Adding this code to ~/.config/fontconfig/fonts.conf (it may need to be created) fixed the issue for me:

<match target="font" >
    <edit name="embeddedbitmap" mode="assign">
        <bool>false</bool>
    </edit>
</match>

This isn't original with me, but I cannot remember where I found the answer as it's been awhile (I just copied my file to here). All I remember is that my searches had to do with Calibri. Hope this helps.