Enable send-side BWE by default.

webrtc/media/engine/webrtcvideoengine2.cc

Index: webrtc/media/engine/webrtcvideoengine2.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2.cc b/webrtc/media/engine/webrtcvideoengine2.cc
index 2dec8f43b6c738875eabb4bb1f252608382ec9d0..ea1926b38857bf9f15e71811e91c616b914d8ba2 100644
--- a/webrtc/media/engine/webrtcvideoengine2.cc
+++ b/webrtc/media/engine/webrtcvideoengine2.cc
@@ -580,11 +580,9 @@ RtpCapabilities WebRtcVideoEngine2::GetCapabilities() const {
   capabilities.header_extensions.push_back(
       webrtc::RtpExtension(webrtc::RtpExtension::kVideoRotationUri,
                            webrtc::RtpExtension::kVideoRotationDefaultId));
-  if (webrtc::field_trial::FindFullName("WebRTC-SendSideBwe") == "Enabled") {
-    capabilities.header_extensions.push_back(webrtc::RtpExtension(
-        webrtc::RtpExtension::kTransportSequenceNumberUri,
-        webrtc::RtpExtension::kTransportSequenceNumberDefaultId));
-  }
+  capabilities.header_extensions.push_back(webrtc::RtpExtension(
+      webrtc::RtpExtension::kTransportSequenceNumberUri,
+      webrtc::RtpExtension::kTransportSequenceNumberDefaultId));
   capabilities.header_extensions.push_back(
       webrtc::RtpExtension(webrtc::RtpExtension::kPlayoutDelayUri,
                            webrtc::RtpExtension::kPlayoutDelayDefaultId));