You can't install buggy plugins or extensions on your iPhone. Try removing some of your Chrome extensions down and you'll be back in the 50MB range.
It's clear from my own experience, posts here, and benchmarks that Chrome has strayed from it's original design goals of being a lightweight browser. My reference to this iPhone was just to point out that I think it's a issue with Chrome itself, and not the underlining webkit browser.
It's clear that it's fashionable in certain circles to claim this. It's also clear that these claims are based on subjective impressions rather than anything measured, which makes me suspicious given that an effect of that magnitude should be obvious and I haven't seen any sign of it.
If you have actual data showing that the current Chrome browser performs worse than it used to, I'm sure the Chrome development team would love to see it.