Fix Gn untracked headers in webrtc/p2p.

This CL is the same CL we had at https://codereview.webrtc.org/3016513002/.
Since we cannot land it with Rietveld anymore let's move the discussion
to Gerrit.

BUG=webrtc:7646
CQ_INCLUDE_TRYBOTS=master.internal.tryserver.corp.webrtc:linux_internal

No-Try: True
Change-Id: I442660e6dc71612d6bbcf73764bd4c6f65fcb760
Reviewed-on: https://webrtc-review.googlesource.com/7982
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Henrik Kjellander <kjellander@google.com>
Cr-Commit-Position: refs/heads/master@{#20257}
diff --git a/p2p/BUILD.gn b/p2p/BUILD.gn
index 9f655a7..eba6b68 100644
--- a/p2p/BUILD.gn
+++ b/p2p/BUILD.gn
@@ -26,6 +26,7 @@
     "base/basicpacketsocketfactory.cc",
     "base/basicpacketsocketfactory.h",
     "base/candidate.h",
+    "base/candidatepairinterface.h",
     "base/common.h",
     "base/dtlstransport.cc",
     "base/dtlstransport.h",
@@ -116,11 +117,14 @@
     }
   }
 
+  # TODO(deadbeef): code under p2p/quic and base/transportchannelimpl.h should be
+  # removed. See bugs.webrtc.org/8385.
   if (rtc_use_quic) {
     deps = [
       "//third_party/libquic",
     ]
     sources += [
+      "base/transportchannelimpl.h",
       "quic/quicconnectionhelper.cc",
       "quic/quicconnectionhelper.h",
       "quic/quicsession.cc",
@@ -225,6 +229,7 @@
 rtc_static_library("libstunprober") {
   sources = [
     "stunprober/stunprober.cc",
+    "stunprober/stunprober.h",
   ]
 
   if (!build_with_chromium && is_clang) {