Enable cpplint and fix cpplint errors in webrtc/*audio

webrtc/common_audio/resampler/push_resampler.cc

Index: webrtc/common_audio/resampler/push_resampler.cc
diff --git a/webrtc/common_audio/resampler/push_resampler.cc b/webrtc/common_audio/resampler/push_resampler.cc
index 788223d343dc99ab9437cf65820a6dd344e2ddf3..ec904b81c8f16fec98132e19c29ea1f8b715fc99 100644
--- a/webrtc/common_audio/resampler/push_resampler.cc
+++ b/webrtc/common_audio/resampler/push_resampler.cc
@@ -53,7 +53,7 @@ void CheckExpectedBufferSizes(size_t src_length,
   RTC_DCHECK_GE(dst_capacity, dst_size_10ms);
 #endif
 }
-}
+}  // namespace
 
 template <typename T>
 PushResampler<T>::PushResampler()