Revert "Merge pull request #16158 from apolcyn/revert_windows_breakage"

This reverts commit d9e8f86675cf923714b3ead4b06087e14a88c08c, reversing
changes made to 04847aeb1e62bc528d88fa3c47daa24a4cf629b3.
diff --git a/BUILD b/BUILD
index ee4b5df..81390dd 100644
--- a/BUILD
+++ b/BUILD
@@ -1433,7 +1433,10 @@
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_posix.cc",
+        "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_windows.cc",
         "src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.cc",
     ],
     hdrs = [