It's not yet, but I'm pretty sure the allocations are happening in the 3D engine I'm using. (I mean the chrome tools aren't telling me that, but when I let the game run without rendering the sawtooth goes away.)

Actually now that I take a second look, some relatively simple demos of the same engine (Babylon.js) show the same sort of behavior. Some rather trivial three.js demos do as well. I might be dealing with something that's just a fact of life for webGL rendering.

Random example (not mine) showing a vaguely similar sawtooth of heap memory usage:

http://gleborgne.github.io/molvwr/#1GCN

hey tehlike - I work on streak.com and we have some pretty interesting memory challenges being a full blown web app running inside of another very complex web app (gmail). Any interest in poking around and helping us with memory issues?