Allow external TaskQueue implementations on Linux

webrtc/pc/BUILD.gn

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 import("../webrtc.gni")
 if (is_android) {
@@ skipping 208 matching lines @@
   }
 }
 
 rtc_source_set("libjingle_peerconnection") {
   public_deps = [
     ":create_pc_factory",
     ":peerconnection",
     "../api:libjingle_peerconnection_api",
   ]
 
+  # This target always link with a default implementation
+  # regardless of the flag |rtc_link_task_queue_impl|.
+  deps = [
+    "../rtc_base:rtc_task_queue_impl",
+  ]
+
   if (rtc_use_quic) {
     sources += [
       "quicdatachannel.cc",
       "quicdatachannel.h",
       "quicdatatransport.cc",
       "quicdatatransport.h",
     ]
     deps += [ "//third_party/libquic" ]
     public_deps = [
       "//third_party/libquic",
@@ skipping 218 matching lines @@
       "//testing/gmock",
     ]
 
     if (is_android) {
       deps += [ "//testing/android/native_test:native_test_support" ]
 
       shard_timeout = 900
     }
   }
 }