Thats part of Google's crusade against weak ciphers etc.
For example they are phasing out SHA-1
Summary
The use of SHA-1 within TLS certificates is no longer sufficiently secure. This is an intent to phase them out (in 2-3 years). In order to make such a phase-out execute smoothly, rather than be an Internet flag day, we will be degrading the experience when these certificates are used in the wild.
The following changes to Chromium's handling of SHA-1 are proposed:
- All SHA-1-using certificates that are valid AFTER 2017/1/1 are treated insecure, but without an interstitial. That is, they will receive a degraded UI indicator, but users will NOT be directed to click through an error page.
- Additionally, the mixed content blocker will be taught to treat these as mixed content, which WILL require a user action to interact with.
- All SHA-1-using certificates that are valid AFTER 2016/1/1 are treated as insecure, but without an interstitial. They will receive a degraded UI indicator, but will NOT be treated as mixed content.