Asess chrome performance

It appears that sometimes, graphics can slow down dramatically on large or long-running chrome tabs.  It is quite possibly a broader Chrome/WebGL issue. 

See https://code.google.com/p/chromium/issues/detail?id=180119
via https://www.google.com/search?q=chrome+webgl+slower+than+firefox+or+safari&oq=chrome+webgl+sl&aqs=chrome.1.69i57j69i59j0.3863j0j7&sourceid=chrome&espv=210&es_sm=91&ie=UTF-8
