Apple's new hardware approach might work well for this: on the A12X chip used by the new iPad Pro, they have 4 high performance cores and 4 low power cores. Let Chrome have a couple low power cores, and that solves a few problems:

1. I get security isolation between Chrome and the rest of my apps. 2. I no longer care very much when poorly written javascript wants to consume 100% of CPU because it's only running on a low power core. 3. My battery life is also better because Chrome can't consume a high power core.