Moved transport.h from webrtc/ to webrtc/api, created build target and updated dependencies.

webrtc/modules/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("../build/webrtc.gni")
 import("audio_coding/audio_coding.gni")
@@ skipping 604 matching lines @@
     if (is_win) {
       cflags = [
         # TODO(kjellander): bugs.webrtc.org/261: Fix this warning.
         "/wd4373",  # virtual function override.
       ]
     }
 
     deps += [
       ":audio_network_adaptor_unittests",
       "..:webrtc_common",
+      "../api:transport_api",
       "../base:rtc_base",  # TODO(kjellander): Cleanup in bugs.webrtc.org/3806.
       "../common_audio",
       "../common_video",
       "../system_wrappers:system_wrappers",
       "../test:rtp_test_utils",
       "../test:test_common",
       "../test:test_support_main",
       "../test:video_test_common",
       "audio_coding",
       "audio_coding:acm_receive_test",
@@ skipping 98 matching lines @@
       "../test:test_common",
       "../test:test_support_main",
       "remote_bitrate_estimator:bwe_simulator_lib",
       "video_capture",
       "//testing/gmock",
       "//testing/gtest",
       "//third_party/gflags",
     ]
   }
 }