UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.75 Safari/537.36

Steps to reproduce the problem:
1. Load Chrome in the Unity window manager, ensuring Chrome and Unity are using GPU acceleration.
2. Load a page in Chrome that is constantly updating the screen--an animated GIF works well, like http://giphy.com/gifs/gonwild-esseract-j0EcojD7hIvuM
3. Perform other activities in Chrome or in other applications that involve redraws. For example, bring a large window to the foreground, and then another large window to the foreground. There's also a more noticeable lag in text entry (though more subtle). Resizing windows, especially Chrome windows, may also show the increased lag of the graphics subsystem.
3. Run Chrome with --disable-gpu, or under another window manager, like XFCE and these issues are not present.

What is the expected behavior?
Expect that Chrome behaves at least as well using GPU acceleration as when it is not.

What went wrong?
System is less responsive and feels much slower.

Did this work before? No 

Chrome version: 50.0.2661.75  Channel: stable
OS Version: 
Flash Version: Shockwave Flash 21.0 r0

My hardware is a very modern desktop (HP Z440) with a Quadro K620 GPU (2GB RAM). The card has >1GB free FB RAM when this is happening. I don't see any high GPU memory usage or high idle wakeups in the Chrome Task Manager.

Note that this issue is easier to see on a high resolution screen, as things like bringing a large window to the foreground are more intensive operations.