Reland "Move smoothing filter to common audio".

webrtc/BUILD.gn

Index: webrtc/BUILD.gn
diff --git a/webrtc/BUILD.gn b/webrtc/BUILD.gn
index 242d8ea981008598045748609b6648a2cbc9f760..90d8c36d99e359b3e03d7624e75f4701860d5400 100644
--- a/webrtc/BUILD.gn
+++ b/webrtc/BUILD.gn
@@ -363,6 +363,7 @@ if (rtc_include_tests) {
     testonly = true
     sources = [
       "api/fakemetricsobserver.cc",
+      "base/analytics/exp_filter_unittest.cc",
       "base/array_view_unittest.cc",
       "base/atomicops_unittest.cc",
       "base/autodetectproxy_unittest.cc",
@@ -380,7 +381,6 @@ if (rtc_include_tests) {
       "base/criticalsection_unittest.cc",
       "base/event_tracer_unittest.cc",
       "base/event_unittest.cc",
-      "base/exp_filter_unittest.cc",
       "base/file_unittest.cc",
       "base/filerotatingstream_unittest.cc",
       "base/fileutils_unittest.cc",
@@ -511,6 +511,7 @@ if (rtc_include_tests) {
       "base:rtc_base",
       "base:rtc_base_tests_utils",
       "base:rtc_task_queue",
+      "base/analytics:rtc_analytics",
       "p2p:libstunprober",
       "p2p:rtc_p2p",
       "//testing/gmock",