Add an ICE switch reason for a switch requested by an application.

Also added an enum for unknown reason.

New value uses a macro-like name rather than a constant-like name for consistency.

Bug: chromium:1369096, webrtc:14131
Change-Id: Ib315584ec40d8c1cd9a6f0ff44587c0d92c735d5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/292341
Reviewed-by: Jonas Oreland <jonaso@webrtc.org>
Commit-Queue: Sameer Vijaykar <samvi@google.com>
Cr-Commit-Position: refs/heads/main@{#39262}

p2p/base/ice_switch_reason.cc

@@ -36,6 +36,9 @@ std::string IceSwitchReasonToString(IceSwitchReason reason) {
       return "selected candidate pair destroyed";
     case IceSwitchReason::ICE_CONTROLLER_RECHECK:
       return "ice-controller-request-recheck";
+    case IceSwitchReason::APPLICATION_REQUESTED:
+      return "application requested";
+    case IceSwitchReason::UNKNOWN:
     default:
       return "unknown";
   }

p2p/base/ice_switch_reason.h

@@ -18,6 +18,7 @@
 namespace cricket {
 
 enum class IceSwitchReason {
+  UNKNOWN,
   REMOTE_CANDIDATE_GENERATION_CHANGE,
   NETWORK_PREFERENCE_CHANGE,
   NEW_CONNECTION_FROM_LOCAL_CANDIDATE,
@@ -31,6 +32,8 @@ enum class IceSwitchReason {
   // P2PTransportChannel to recheck a switch periodically without an event
   // taking place.
   ICE_CONTROLLER_RECHECK,
+  // The webrtc application requested a connection switch.
+  APPLICATION_REQUESTED,
 };
 
 RTC_EXPORT std::string IceSwitchReasonToString(IceSwitchReason reason);