Enable cpplint and fix cpplint errors in webrtc/*audio

webrtc/common_audio/vad/vad_sp_unittest.cc

Index: webrtc/common_audio/vad/vad_sp_unittest.cc
diff --git a/webrtc/common_audio/vad/vad_sp_unittest.cc b/webrtc/common_audio/vad/vad_sp_unittest.cc
index 1e335e362f10d430859aa333871d5848f509da22..e8413086d35b4edf9838687d701ed1353b46b9c6 100644
--- a/webrtc/common_audio/vad/vad_sp_unittest.cc
+++ b/webrtc/common_audio/vad/vad_sp_unittest.cc
@@ -19,7 +19,8 @@ extern "C" {
 #include "webrtc/common_audio/vad/vad_sp.h"
 }
 
-namespace {
+namespace webrtc {
+namespace test {
 
 TEST_F(VadTest, vad_sp) {
   VadInstT* self = reinterpret_cast<VadInstT*>(malloc(sizeof(VadInstT)));
@@ -71,4 +72,5 @@ TEST_F(VadTest, vad_sp) {
 
   free(self);
 }
-}  // namespace
+}  // namespace test
+}  // namespace webrtc