For example, v8 - a very important part of Chromium - is not developed fully openly: major features are developed secretly and land as surprises, like CrankShaft and TurboFan, and also daily development consists of patches landing with little or no public discussion behind them.
Beyond JS engines, you must appreciate that dependencies and business relationships can get very odd when shipping something as big and complicated as a browser. Chrome/Chromium absolutely experiences this, but so does Mozilla. Take HTML EME, where Adobe's technical requirements have pretty much forced Mozilla to break Andreas' and Brendan's original promises on how much the closed-source CDM will be sandboxed. Then there's the h.264 situation, which is an odd multi-step dance to deliver binaries from Cisco, and is significantly more convoluted than Chrome's use of ffmpeg.
Regardless, I don't believe you're really trying to make the argument that Chromium is not a publicly developed open source project with a huge pool of non-Google contributors. Because you know that to simply be an indisputable fact, even if there is additional complexity around certain dependencies and platforms.
I hope a UX person can have a good look at this sometime.
I always thought the system for displaying the bookmarks bar was a bit daft because you could only see about 10 bookmarks before running out of horizontal room. On OSX at least we have a dedicated "Bookmarks" menu but using it under Linux and Windows was always painful due to this strange (IMHO) design.