Ensures that modules_unittests runs on iOS

webrtc/modules/audio_processing/agc/pitch_based_vad_unittest.cc

Index: webrtc/modules/audio_processing/agc/pitch_based_vad_unittest.cc
diff --git a/webrtc/modules/audio_processing/agc/pitch_based_vad_unittest.cc b/webrtc/modules/audio_processing/agc/pitch_based_vad_unittest.cc
index 3ec0baac95cc4fb4e3f193a122b1b40a62f2948e..6526019edc4fe1fb33512a82e64a990c25a894a0 100644
--- a/webrtc/modules/audio_processing/agc/pitch_based_vad_unittest.cc
+++ b/webrtc/modules/audio_processing/agc/pitch_based_vad_unittest.cc
@@ -16,10 +16,11 @@
 
 #include "gtest/gtest.h"
 #include "webrtc/test/testsupport/fileutils.h"
+#include "webrtc/test/testsupport/gtest_disable.h"
 
 namespace webrtc {
 
-TEST(PitchBasedVadTest, VoicingProbabilityTest) {
+TEST(PitchBasedVadTest, DISABLED_ON_IOS(VoicingProbabilityTest)) {
   std::string spectral_peak_file_name = test::ResourcePath(
       "audio_processing/agc/agc_spectral_peak", "dat");
   FILE* spectral_peak_file = fopen(spectral_peak_file_name.c_str(), "rb");