Chromium/Chrome have already proposed a step in the same direction, pushing your market share figure up to 37.4%. [1]
[1] https://www.chromium.org/Home/chromium-security/marking-http...
[1] https://www.chromium.org/Home/chromium-security/marking-http...
https://groups.google.com/a/chromium.org/forum/#!topic/blink...