Fix Chromium clang plugin warnings

webrtc/modules/audio_processing/splitting_filter.cc

Index: webrtc/modules/audio_processing/splitting_filter.cc
diff --git a/webrtc/modules/audio_processing/splitting_filter.cc b/webrtc/modules/audio_processing/splitting_filter.cc
index b6f642c09d4db448b320748538d485bd731d6449..9f1093569903a3c3d362a090e812700165cfdd2f 100644
--- a/webrtc/modules/audio_processing/splitting_filter.cc
+++ b/webrtc/modules/audio_processing/splitting_filter.cc
@@ -31,6 +31,8 @@ SplittingFilter::SplittingFilter(size_t num_channels,
   }
 }
 
+SplittingFilter::~SplittingFilter() = default;
+
 void SplittingFilter::Analysis(const IFChannelBuffer* data,
                                IFChannelBuffer* bands) {
   RTC_DCHECK_EQ(num_bands_, bands->num_bands());