RTC_EXPORT IceServer, StatsReport::{IdBase,Value}.

The component build test failed close to the end of compilation because
of these three missing symbols, see [1].

[1] - https://ci.chromium.org/p/chromium/builders/try/win_chromium_compile_dbg_ng/435777

Bug: webrtc:9419
Change-Id: Icd32fc195229d612bc7b00451f41dc47e589e638
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/159686
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29770}
diff --git a/api/peer_connection_interface.h b/api/peer_connection_interface.h
index 52422c0..a1280de 100644
--- a/api/peer_connection_interface.h
+++ b/api/peer_connection_interface.h
@@ -201,7 +201,7 @@
     kTlsCertPolicyInsecureNoCheck,
   };
 
-  struct IceServer {
+  struct RTC_EXPORT IceServer {
     IceServer();
     IceServer(const IceServer&);
     ~IceServer();