Google Chrome developer tools works very slow
I've been having similar issues for debugging in Chrome versions 50+ on Mac OS X 10.11.3. The only solution I've found so far is to keep the dev tools docked to the right and it seems to be as performant as before. Not the optimal solution, but it works in my case.
Finally, a solution has been found which helped me after such a long time and after so many failed attempts to fix it: Solution on Google Chrome Forums
Go to chrome://flags/#force-color-profile
Change it to sRGB
Since Google does not allow direct links to chrome://
you'll have to insert the colon by yourself, or enter the whole link manually into your toolbar.