fix python artifact build

BUILD

@@ -478,6 +478,7 @@ grpc_cc_library(
         "src/core/lib/iomgr/ev_epollsig_linux.c",
         "src/core/lib/iomgr/ev_poll_posix.c",
         "src/core/lib/iomgr/ev_posix.c",
+        "src/core/lib/iomgr/ev_windows.c",
         "src/core/lib/iomgr/exec_ctx.c",
         "src/core/lib/iomgr/executor.c",
         "src/core/lib/iomgr/iocp_windows.c",

build.yaml

@@ -316,6 +316,7 @@ filegroups:
   - src/core/lib/iomgr/ev_epollsig_linux.c
   - src/core/lib/iomgr/ev_poll_posix.c
   - src/core/lib/iomgr/ev_posix.c
+  - src/core/lib/iomgr/ev_windows.c
   - src/core/lib/iomgr/exec_ctx.c
   - src/core/lib/iomgr/executor.c
   - src/core/lib/iomgr/iocp_windows.c

src/core/lib/iomgr/ev_windows.c

@@ -0,0 +1,43 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/iomgr/port.h"
+
+#ifdef GRPC_WINSOCK_SOCKET
+
+#include "src/core/lib/debug/trace.h"
+
+grpc_tracer_flag grpc_polling_trace =
+    GRPC_TRACER_INITIALIZER(false); /* Disabled by default */
+
+#endif  // GRPC_WINSOCK_SOCKET