Revert of Enable GN check for webrtc/{ortc,p2p} (patchset #4 id:60001 of https://codereview.webrtc.org/2714263004/ )

Reason for revert:
Fails compile in Chromium for NaCl:
https://build.chromium.org/p/chromium.webrtc.fyi/builders/Win%20Builder/builds/9320/
 http://build.chromium.org/p/chromium.webrtc.fyi/builders/Mac%20Builder/builds/22215
http://build.chromium.org/p/chromium.webrtc.fyi/builders/Linux%20Builder/builds/14501

Original issue's description:
> Enable GN check for webrtc/{ortc,p2p}
>
> Introduce new target //webrtc/p2p:rtc_p2p_test_utils to host
> test-related utilities.
> Previously uncovered header "base/fakecandidatepair.h" is now also in a target.
>
> BUG=webrtc:6828
>
> Review-Url: https://codereview.webrtc.org/2714263004
> Cr-Commit-Position: refs/heads/master@{#17036}
> Committed: https://chromium.googlesource.com/external/webrtc/+/c9515b6ce642875c4994deb25a5bb0132a958848

TBR=deadbeef@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6828

Review-Url: https://codereview.webrtc.org/2735583002
Cr-Commit-Position: refs/heads/master@{#17038}
diff --git a/webrtc/p2p/BUILD.gn b/webrtc/p2p/BUILD.gn
index 6f65bba..07fcdf4 100644
--- a/webrtc/p2p/BUILD.gn
+++ b/webrtc/p2p/BUILD.gn
@@ -83,10 +83,7 @@
   defines = []
 
   deps = [
-    "../api:libjingle_peerconnection_api",
-    "../api:ortc_api",
     "../base:rtc_base",
-    "../system_wrappers",
   ]
 
   if (rtc_build_expat) {
@@ -148,7 +145,13 @@
     sources = [
       "base/asyncstuntcpsocket_unittest.cc",
       "base/dtlstransportchannel_unittest.cc",
+      "base/fakedtlstransport.h",
+      "base/fakeicetransport.h",
+      "base/fakepackettransport.h",
+      "base/fakeportallocator.h",
+      "base/faketransportcontroller.h",
       "base/jseptransport_unittest.cc",
+      "base/mockicetransport.h",
       "base/p2ptransportchannel_unittest.cc",
       "base/port_unittest.cc",
       "base/portallocator_unittest.cc",
@@ -160,6 +163,9 @@
       "base/stunrequest_unittest.cc",
       "base/stunserver_unittest.cc",
       "base/tcpport_unittest.cc",
+      "base/testrelayserver.h",
+      "base/teststunserver.h",
+      "base/testturnserver.h",
       "base/transportcontroller_unittest.cc",
       "base/transportdescriptionfactory_unittest.cc",
       "base/turnport_unittest.cc",
@@ -178,13 +184,7 @@
     }
     deps = [
       ":rtc_p2p",
-      ":rtc_p2p_test_utils",
       "../api:fakemetricsobserver",
-      "../api:ortc_api",
-      "../base:rtc_base",
-      "../base:rtc_base_approved",
-      "../base:rtc_base_tests_utils",
-      "../test:test_support",
       "//testing/gmock",
       "//testing/gtest",
     ]
@@ -194,30 +194,6 @@
     }
     defines = [ "GTEST_RELATIVE_PATH" ]
   }
-
-  rtc_source_set("rtc_p2p_test_utils") {
-    testonly = true
-    sources = [
-      "base/fakecandidatepair.h",
-      "base/fakedtlstransport.h",
-      "base/fakeicetransport.h",
-      "base/fakepackettransport.h",
-      "base/fakeportallocator.h",
-      "base/faketransportcontroller.h",
-      "base/mockicetransport.h",
-      "base/testrelayserver.h",
-      "base/teststunserver.h",
-      "base/testturnserver.h",
-    ]
-    deps = [
-      ":rtc_p2p",
-      "../api:ortc_api",
-      "../base:rtc_base",
-      "../base:rtc_base_approved",
-      "../base:rtc_base_tests_utils",
-      "../test:test_support",
-    ]
-  }
 }
 
 rtc_static_library("libstunprober") {
@@ -232,7 +208,6 @@
   }
 
   deps = [
-    ":rtc_p2p",
     "..:webrtc_common",
     "../base:rtc_base",
   ]
@@ -246,10 +221,6 @@
     ]
     deps = [
       ":libstunprober",
-      ":rtc_p2p",
-      ":rtc_p2p_test_utils",
-      "../base:rtc_base",
-      "../base:rtc_base_tests_utils",
       "//testing/gmock",
       "//testing/gtest",
     ]