When I have Google Chrome open and I switch to other applications by either using alt+tab or just mouse, it takes about a second or so to change focus. Same goes another way around - when I try to switch to Chrome, it takes time. However, when I switch between all other applications, I don't experience any delay. I tried it with Firefox with a dozen of tabs and it's super-fast. Can it be fixed for Chrome? I'm trying it on a very powerful laptop(XPS 15 9550) and don't understand if video adapter can be an issue here.
I started having the same problem with Google Chrome just today (on Ubuntu 16.04).
Switching between tabs on the same Chrome window is fast (just like normal).
Trying to switch focus from one Chrome window to another Chrome window is painfully slow (like 2 second delay). Similarly slow when switching from a Chrome window to another application (e.g. nautilus), but seems slightly less slow (like 1 second delay).
Switching between other non-chrome windows is normal speed. Firefox is fine.
The only thing that's changed for me is : my dell precision m3800 suddenly thinks I'm connected to a lower wattage power adapter (have tried multiple authentic dell adapters, still same problem).
Normally Dell BIOS slows your CPU down to 800mhz in this state, and I ended up setting intel_pstate=disable processor.ignore_ppc=1 in my grub config to force it to ignore that (per Ubuntu 15.04 with intel_pstate - low current cpu frequency).