--- a/netwerk/base/nsSocketTransport2.cpp
+++ b/netwerk/base/nsSocketTransport2.cpp
@@ -779,17 +779,16 @@ nsSocketTransport::nsSocketTransport()
     , mReuseAddrPort(false)
     , mState(STATE_CLOSED)
     , mAttached(false)
     , mInputClosed(true)
     , mOutputClosed(true)
     , mResolving(false)
     , mNetAddrIsSet(false)
     , mSelfAddrIsSet(false)
-    , mNetAddrPreResolved(false)
     , mLock("nsSocketTransport.mLock")
     , mFD(this)
     , mFDref(0)
     , mFDconnected(false)
     , mFDFastOpenInProgress(false)
     , mSocketTransportService(gSocketTransportService)
     , mInput(this)
     , mOutput(this)
@@ -1066,21 +1065,16 @@ nsSocketTransport::ResolveHost()
 {
     SOCKET_LOG(("nsSocketTransport::ResolveHost [this=%p %s:%d%s]\n",
                 this, SocketHost().get(), SocketPort(),
                 mConnectionFlags & nsSocketTransport::BYPASS_CACHE ?
                 " bypass cache" : ""));
 
     nsresult rv;
 
-    if (mNetAddrPreResolved) {
-        mState = STATE_RESOLVING;
-        return PostEvent(MSG_DNS_LOOKUP_COMPLETE, NS_OK, nullptr);
-    }
-
     if (!mProxyHost.IsEmpty()) {
         if (!mProxyTransparent || mProxyTransparentResolvesHost) {
 #if defined(XP_UNIX)
             MOZ_ASSERT(!mNetAddrIsSet || mNetAddr.raw.family != AF_LOCAL,
                        "Unix domain sockets can't be used with proxies");
 #endif
             // When not resolving mHost locally, we still want to ensure that
             // it only contains valid characters.  See bug 304904 for details.

--- a/netwerk/base/nsSocketTransport2.h
+++ b/netwerk/base/nsSocketTransport2.h
@@ -336,17 +336,16 @@ private:
 
     // mNetAddr/mSelfAddr is valid from GetPeerAddr()/GetSelfAddr() once we have
     // reached STATE_TRANSFERRING. It must not change after that.
     void                    SetSocketName(PRFileDesc *fd);
     NetAddr                 mNetAddr;
     NetAddr                 mSelfAddr; // getsockname()
     Atomic<bool, Relaxed>   mNetAddrIsSet;
     Atomic<bool, Relaxed>   mSelfAddrIsSet;
-    Atomic<bool, Relaxed>   mNetAddrPreResolved;
 
     nsAutoPtr<NetAddr>      mBindAddr;
 
     // socket methods (these can only be called on the socket thread):
 
     void     SendStatus(nsresult status);
     nsresult ResolveHost();
     nsresult BuildSocket(PRFileDesc *&, bool &, bool &);