<files-triage>

Related request here: https://bugs.chromium.org/p/chromium/issues/detail?id=843310

The Gallery is just a webcontents renderer, so really we're blocked on support for these in Blink - i.e. Issue 843310, which is Pri-3 (this bug probably should be as well).

After that, it's probably just a case of updating some manifest files to support 
{.heif, .heic} in the ChromeOS gallery as well.

Currently, no browser supports this image format -- https://caniuse.com/#feat=heif . Not even Safari on macOS, where the file format is apparently supported natively (That conflicts with a statement on https://blog.filestack.com/thoughts-and-knowledge/heif-versus-jpeg/ which says Safari 11 supports it. Anecdotally, I tried Safari 11.1.1 and it did not open a .heic file).

There *are* (at least two) implementations in Javascript. One is copyright Nokia with a custom license -- http://github.com/nokiatech/heif -- and other is LGPL -- https://github.com/strukturag/libheif

except for licencing, incorporating these into the gallery would be possible if this is really urgent.. There's already some LGPL stuff in Chrome.