Yes, I did try to disable extensions but my Gmail issue continues, and now sometimes it works but mostly not.
One odd symptom is that clicking on Gmail in my speed dial fails to prompt me for ID and Password like it does in Safari. Instead I get the Loading msg and either no blue loading status line, or more often no blue loading status line. Just now I closed Chrome and restarted and the same thing happened - no Gmail prompt and only half a blue line. I have also cleared my cached file several times without success.
Once this morning with extensions disabled (therefore no speed dial) I tried Gmail, again without success.
I'm wondering whether I should just wait for 10.10.4 and just Safari for Gmail. How often do these updates come out?