Reland "Move smoothing filter to common audio".

webrtc/base/analytics/BUILD.gn

Index: webrtc/base/analytics/BUILD.gn
diff --git a/webrtc/base/analytics/BUILD.gn b/webrtc/base/analytics/BUILD.gn
new file mode 100644
index 0000000000000000000000000000000000000000..e7e631dca6029b842a4ccf213cb53b3332de76d4
--- /dev/null
+++ b/webrtc/base/analytics/BUILD.gn
@@ -0,0 +1,16 @@
+# 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")
+
+rtc_static_library("rtc_analytics") {
+  sources = [
+    "exp_filter.cc",
+    "exp_filter.h",
+  ]
+}