Remove ContainsKey where relevant #6282
Each instance of ContainsKey that I deleted was followed by querying the same dictionary for the same key. These can be done at the same time, so I replaced them.
I do not expect that this will have any substantial user impact, but it theoretically improves perf, and it's a pet peeve of mine.
Forgind left a comment
I have a few unrelated changes like in RoslynCodeTaskFactory, but I think it's all fairly straightforward. Also, some of my variable names are bad. If you have better ideas, please suggest them.