I don't understand your point. If there were such a difference between Chromium and Chrome, then it would surely show up in a diff of the binaries' disassemblies. The size of the binaries doesn't matter, because (assuming you trust the Chromium source and your local system) only the difference between the two is relevant.

My point is that it will show up in a diff of the binaries.

Isn't that what I said?

I said that the binaries could be diffed, then you responded that finding a difference is unlikely because the binary is very large. I don't understand what the absolute size of the binaries has to do with being able to compare them.