Add "ice-option:trickle" to generated offers/answers.

webrtc/pc/mediasession_unittest.cc

Index: webrtc/pc/mediasession_unittest.cc
diff --git a/webrtc/pc/mediasession_unittest.cc b/webrtc/pc/mediasession_unittest.cc
index 7fe4b51fa8b0f7775040534e973cb8e357b1fbd2..a1d6a6d0c393b47fba208c9cddf3f5b15f42793d 100644
--- a/webrtc/pc/mediasession_unittest.cc
+++ b/webrtc/pc/mediasession_unittest.cc
@@ -262,8 +262,8 @@ class MediaSessionDescriptionFactoryTest : public testing::Test {
   bool GetIceRenomination(const TransportInfo* transport_info) {
     const std::vector<std::string>& ice_options =
         transport_info->description.transport_options;
-    auto iter = std::find(ice_options.begin(), ice_options.end(),
-                          cricket::ICE_RENOMINATION_STR);
+    auto iter =
+        std::find(ice_options.begin(), ice_options.end(), "renomination");
     return iter != ice_options.end();
   }