What does the Chrome JavaScript CPU profiler do that could affect a program's performance (during the profile)?
We noticed considerable performance degradation when DevTools are open. The problem appeared about 2-3 months ago. With DevTools open our QUnit tests start very slowly. The page just hanged for several seconds before tests are starting to go. We have rather big application with about 10Mb of JavaScript and dependencies. I suppose that you may have faced a similar problem.
Here is a list of active Chromium issues (it's an open source base for the Chrome browser):https://code.google.com/p/chromium/issues/listBy searching for "devtools performance" it gives me several screens of issues.