Do not create a temporary transport channel when using max-bundle

webrtc/pc/channel.cc

Index: webrtc/pc/channel.cc
diff --git a/webrtc/pc/channel.cc b/webrtc/pc/channel.cc
index 4d47e878b8e2b8c7d7c858c439d822f9d95a4720..1ef193aaa311a30e0d01ccf201cc24ab074cbf29 100644
--- a/webrtc/pc/channel.cc
+++ b/webrtc/pc/channel.cc
@@ -195,8 +195,8 @@ BaseChannel::~BaseChannel() {
   LOG(LS_INFO) << "Destroyed channel";
 }
 
-bool BaseChannel::Init() {
-  if (!SetTransport(content_name())) {
+bool BaseChannel::Init(const std::string& transport_name) {
+  if (!SetTransport(transport_name)) {
     return false;
   }
 
@@ -1346,8 +1346,8 @@ VoiceChannel::~VoiceChannel() {
   Deinit();
 }
 
-bool VoiceChannel::Init() {
-  if (!BaseChannel::Init()) {
+bool VoiceChannel::Init(const std::string& transport_name) {
+  if (!BaseChannel::Init(transport_name)) {
     return false;
   }
   return true;
@@ -1667,8 +1667,8 @@ VideoChannel::VideoChannel(rtc::Thread* thread,
                   content_name,
                   rtcp) {}
 
-bool VideoChannel::Init() {
-  if (!BaseChannel::Init()) {
+bool VideoChannel::Init(const std::string& transport_name) {
+  if (!BaseChannel::Init(transport_name)) {
     return false;
   }
   return true;
@@ -1911,8 +1911,8 @@ DataChannel::~DataChannel() {
   Deinit();
 }
 
-bool DataChannel::Init() {
-  if (!BaseChannel::Init()) {
+bool DataChannel::Init(const std::string& transport_name) {
+  if (!BaseChannel::Init(transport_name)) {
     return false;
   }
   media_channel()->SignalDataReceived.connect(