Google incorporated a big change for Chrome on Windows by switching the browser to the Clang compiler. Previously, Google used Microsoft's C++ compiler but now the search giant is using the same compiler across all platforms, including Windows, macOS, Linux, and Android.
As ARS Technica points out, this makes Chrome the first major software project to adopt Clang on Windows.
Way back in 2013, Google decided that it wanted to use Clang everywhere, including Windows. Using the same compiler everywhere makes development much easier—you have the same set of bugs to deal with on every platform—and Clang in particular has diagnostic tools such as ASan and UBSan that Google wanted to be able to use.