I’d guess so. The original Chrome for iOS announcement [1] said:
it’s been challenging to re-use critical Chromium infrastructure components. That said, there is a lot of code we do leverage, such as the network layer, the sync and bookmarks infrastructure, omnibox, metrics and crash reporting, and a growing portion of content.
Precisely the reason I don't care that the other big browser engines can't be ported to iOS. Their concern for battery life/power drain is so low that there's zero chance I'd use them anyway. I don't even use them on the "desktop" (laptop) anymore, for that reason.