Comment 8 for bug 988337

It happened to me too and I found a solution:

1) Open /usr/share/applications/google-chrome.desktop with sudo privileges in some editor.

2) Open Chromium or Chrome browser. Does not matter, if it shows in a different icon or not.

3) Open a terminal and type:

xprop | grep WM_CLASS

4) Your mouse pointer will change into a cross. With this cross click anywhere inside the Chrome/ium window. Something like this will show up in the terminal:

WM_CLASS(STRING) = "Google-chrome-stable", "Google-chrome-stable"

5) In the editor, in which you opened the *.desktop file, write on the second line (after the [Desktop Entry]):

StartupWMClass=Google-chrome-stable

or StartupWMClass=whatever was in the terminal output (in either of the quotes).

6)Save the file and the result should be seen immediately.

Cheers.