Add a turn port prune policy to keep the first ready turn port.

Bug: webrtc:11026
Change-Id: I6222e9613ee4ce2dcfbb717e2430ea833c0dc373
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/155542
Commit-Queue: Honghai Zhang <honghaiz@webrtc.org>
Reviewed-by: Qingsi Wang <qingsi@webrtc.org>
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Jonas Oreland <jonaso@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29470}
diff --git a/pc/peer_connection_interface_unittest.cc b/pc/peer_connection_interface_unittest.cc
index 2d0687c..5a01430 100644
--- a/pc/peer_connection_interface_unittest.cc
+++ b/pc/peer_connection_interface_unittest.cc
@@ -1395,7 +1395,8 @@
   EXPECT_TRUE(raw_port_allocator->flags() & cricket::PORTALLOCATOR_DISABLE_TCP);
   EXPECT_TRUE(raw_port_allocator->flags() &
               cricket::PORTALLOCATOR_DISABLE_COSTLY_NETWORKS);
-  EXPECT_TRUE(raw_port_allocator->prune_turn_ports());
+  EXPECT_EQ(webrtc::PRUNE_BASED_ON_PRIORITY,
+            raw_port_allocator->turn_port_prune_policy());
 }
 
 // Check that GetConfiguration returns the configuration the PeerConnection was
@@ -2448,11 +2449,12 @@
   config.prune_turn_ports = false;
   CreatePeerConnection(config);
   config = pc_->GetConfiguration();
-  EXPECT_FALSE(port_allocator_->prune_turn_ports());
+  EXPECT_EQ(webrtc::NO_PRUNE, port_allocator_->turn_port_prune_policy());
 
   config.prune_turn_ports = true;
   EXPECT_TRUE(pc_->SetConfiguration(config).ok());
-  EXPECT_TRUE(port_allocator_->prune_turn_ports());
+  EXPECT_EQ(webrtc::PRUNE_BASED_ON_PRIORITY,
+            port_allocator_->turn_port_prune_policy());
 }
 
 // Test that the ice check interval can be changed. This does not verify that