Add third_party/webrtc_overrides.

third_party/webrtc_overrides/webrtc/base/win32socketinit.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Redirect WebRTC's winsock initialization activity into Chromium's
+// singleton object that managest precisely that for the browser.
+
+#include "third_party/webrtc/base/win32socketinit.h"
+
+#include "net/base/winsock_init.h"
+
+#if !defined(WEBRTC_WIN)
+#error "Only compile this on Windows"
+#endif
+
+namespace rtc {
+
+void EnsureWinsockInit() {
+  net::EnsureWinsockInit();
+}
+
+}  // namespace rtc