Added an empty AudioTransportProxy to AudioState.

webrtc/audio/BUILD.gn

Index: webrtc/audio/BUILD.gn
diff --git a/webrtc/audio/BUILD.gn b/webrtc/audio/BUILD.gn
index 127900544cb55dfa9b4ed414e5f884d378b7856d..abdc96806d252cf05b33a116bade28a6409532a0 100644
--- a/webrtc/audio/BUILD.gn
+++ b/webrtc/audio/BUILD.gn
@@ -16,6 +16,7 @@ rtc_static_library("audio") {
     "audio_send_stream.h",
     "audio_state.cc",
     "audio_state.h",
+    "audio_transport_proxy.h",
     "conversion.h",
     "scoped_voe_interface.h",
   ]
@@ -29,6 +30,9 @@ rtc_static_library("audio") {
     "..:webrtc_common",
     "../api:audio_mixer_api",
     "../api:call_api",
+    "../base:rtc_base_approved",
+    "../modules/audio_device",
+    "../modules/audio_processing",
     "../system_wrappers",
     "../voice_engine",
   ]
@@ -50,5 +54,13 @@ if (rtc_include_tests) {
       # Suppress warnings from the Chromium Clang plugin (bugs.webrtc.org/163).
       suppressed_configs += [ "//build/config/clang:find_bad_constructs" ]
     }

[aleloi, 2016/11/01 15:53:34]

Caused by including gmock file.

+    if (is_win) {
+      cflags = [
+        # TODO(phoglund): get rid of 4373 supression when
+        # http://code.google.com/p/webrtc/issues/detail?id=261 is solved.
+        # legacy warning for ignoring const / volatile in signatures.
+        "/wd4373",
+      ]
+    }
   }
 }