Trying to change my question
OS: Mac OSX 10.12.2 Browser: Chrome 55.0.2883.95 (64-bit)
I am in one tab - for example writing a comment or answer in StackOverflow when out of the blue with a tweety sound, "chrome://apps" page replaces the page I am on.
Is it some kind of key/mouse/swipe combo I have not noticed that I do with my magic mouse?
on a bountied question, I am told I need 300 points to create the tag macos - I am doing no such thing.
Please help me update my question