UPDATE 2 (September 08):

Google has confirmed that Photos’ iOS client now supports both HEIF and HEVC camera formats. The confirmation came in the from of a tweet from none other than David Lieb, who is product lead at Google Photos.

UPDATE 1 :

Google Photos on supporting iOS 11’s new camera formats

#gHelp The Google Photos team is working on bringing HEIC support, likely by September's release of iOS11 (1/2) — Nadia Llentirb (@NadiaLlentirb) August 3, 2017

iOS 11’s new camera formats HEIF and HEVC may soon be supported on Google’s Photos app. David Lieb – who is Product lead at Google Photos – revealed that they are working on the feature.

We're on it — David Lieb (@dflieb) June 30, 2017

HEIF photo and HEVC video formats, for those who aren’t aware, promise to not only improve image quality, but also save half of the storage on iOS 11. We are keeping an eye on every Google Photos-related development. In case the feature rolls out, we’ll definitely inform you.