Fix chromium-style errors in IntelligibilityEnhancer

webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc

Index: webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
diff --git a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
index dfa912b31f7087fa1e98f0a9dcb1d05a19fd4634..6e641a23325984bee6daab921a67c9acc959a489 100644
--- a/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
+++ b/webrtc/modules/audio_processing/intelligibility/intelligibility_utils.cc
@@ -56,6 +56,8 @@ GainApplier::GainApplier(size_t freqs, float relative_change_limit)
       target_(freqs, 1.f),
       current_(freqs, 1.f) {}
 
+GainApplier::~GainApplier() {}
+
 void GainApplier::Apply(const std::complex<float>* in_block,
                         std::complex<float>* out_block) {
   for (size_t i = 0; i < num_freqs_; ++i) {