Reland "Add winmm.lib as a Windows dep for timeutils."

This is a reland of 9e06ce0afbe0319509b3c4cd2494ae9330662926

Original change's description:
> Add winmm.lib as a Windows dep for timeutils.
>
> timeutils.cc uses timeGetTime, which is from winmm.
>
> Bug: None
> Change-Id: I8e40f1c01c1128a80e9b5c59c0b28d39b3d0893a
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128521
> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
> Commit-Queue: Oleh Prypin <oprypin@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#27172}

TBR=oprypin@webrtc.org

Bug: None
Change-Id: Iba69b1a7b92d5d8e9d909e1967194daa2567878b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/128564
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27184}
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index a396a63..ffa43bb 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -410,6 +410,10 @@
     ":safe_conversions",
     ":stringutils",
   ]
+  libs = []
+  if (is_win) {
+    libs += [ "winmm.lib" ]
+  }
 }
 
 rtc_source_set("stringutils") {