The latest version of chromium 43.0.2357.65 does not properly display the UI icon in the task list or alt-tab UI. There is a fix upstream here: https://codereview.chromium.org/1146013005 Reproducible: Always
Created attachment 403820 [details, diff] files/chromium-missing-icon.patch
Created attachment 403822 [details] chromium-43.0.2357.65.ebuild
Confirming bug. Also confirming the attached bug worked for me, too.
I'm not backporting an icon fix. If it hits a stable release, we will get it automatically.