Move talk/session/media -> webrtc/pc

The libjingle_p2p target is renamed to rtc_pc.
The libjingle_p2p_unittest test will be renamed in a
separate follow-up CL, to make it possible to run all
trybots successfully for this CL.

BUG=webrtc:5419
R=deadbeef@webrtc.org, pthatcher@webrtc.org, tommi@webrtc.org

Review URL: https://codereview.webrtc.org/1691463002 .

Cr-Commit-Position: refs/heads/master@{#11592}
diff --git a/webrtc/api/api.gyp b/webrtc/api/api.gyp
index 1efd531..34a75f6 100644
--- a/webrtc/api/api.gyp
+++ b/webrtc/api/api.gyp
@@ -255,7 +255,7 @@
       'type': 'static_library',
       'dependencies': [
         '<(webrtc_root)/media/media.gyp:rtc_media',
-        '../../talk/libjingle.gyp:libjingle_p2p',
+        '<(webrtc_root)/pc/pc.gyp:rtc_pc',
       ],
       'sources': [
         'audiotrack.cc',