Remove third_party/libjingle and update GN targets.

extensions/BUILD.gn

 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//extensions/features/features.gni")
 import("//testing/test.gni")
 import("//tools/grit/grit_rule.gni")
 import("//tools/grit/repack.gni")
 
 assert(enable_extensions)
 
@@ skipping 294 matching lines @@
     "//sdch",
     "//skia",
     "//testing/gmock",
     "//testing/gtest",
     "//testing/perf",
     "//third_party/WebKit/public:blink",
     "//third_party/cacheinvalidation",
     "//third_party/icu",
     "//third_party/leveldatabase",
     "//third_party/libaddressinput",
-    "//third_party/libjingle",
     "//third_party/webrtc/modules/desktop_capture",
+    "//third_party/webrtc_overrides",
     "//third_party/widevine/cdm:headers",
     "//ui/accessibility:test_support",
     "//ui/base:test_support",
     "//ui/compositor:test_support",
     "//ui/resources",
     "//ui/web_dialogs:test_support",
     "//v8",
   ]
 
   if (is_chromeos) {
@@ skipping 31 matching lines @@
     "//testing/gtest",
     "//third_party/hunspell",
     "//third_party/icu",
     "//third_party/libpng",
     "//third_party/zlib",
     "//ui/base:test_support",
     "//ui/resources:ui_test_pak",
     "//ui/web_dialogs:test_support",
   ]
 }