Roll forward to cl/340537221

Signed-off-by: hai007 <hais@google.com>

cpp/platform/api/webrtc.h

@@ -33,6 +33,10 @@ class WebRtcMedium {
 
   virtual ~WebRtcMedium() = default;
 
+  // Gets the default two-letter country code associated with current locale.
+  // For example, en_US locale resolves to "US".
+  virtual const std::string GetDefaultCountryCode() = 0;
+
   // Creates and returns a new webrtc::PeerConnectionInterface object via
   // |callback|.
   virtual void CreatePeerConnection(webrtc::PeerConnectionObserver* observer,