Two other reasons that haven't been mentioned yet: - MSVC had trouble with dead code elimination in some cases: fixing https://crbug.com/684105 https://crbug.c

Two other reasons that haven't been mentioned yet: - MSVC had trouble with dead code elimination in some cases: fixing https://crbug.com/684105 https://crbug.com/684105 reduced binary size by almost 900KB on Windows. - It lets tooling like https://chromium.googlesource.com/chromium/src/+/master/docs/clang_tool_refactoring.md https://chromium.googlesource.com/chromium/src/+/master/docs... and the custom clang plugin checks run on Windows-specific code.