Earlier quoted context omitted.
Google's browser engine is open source. You can reuse Google's browser engine meaning that you can focus on the features that differentiate your browser instead of implementing the spec like you suggest.
Exactly, in that model the only way to build a browser is to depend on someone else to implement the specs. It's not feasible to build a new browser, at best you can start with what Google implemented, including proprietary features, and go from there. At that point you likely don't understand the codebase fully and are going to be dependant on staying in sync with chromium to get new features. This model of starting…
It's faster to learn the part of the comebase you are interested in rather than building a whole browser engine.
>and are going to be dependant on staying in sync with chromium to get new features.
Being able to reuse the work Google is investing into th browser engine is a positive.
>There isn't much daylight between that and the often complained about limitation of Apple only allowing the use of WebKit on iOS.
The difference is you can make changes to the browser engine if you need.