Delete unused C functions wrapping the WavWriter class

Bug: None
Change-Id: Iea766c76e99f066a4cdad0d5039e266a6bba7664
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/141660
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28262}
diff --git a/common_audio/wav_file.cc b/common_audio/wav_file.cc
index 77b46e7..2170b7e 100644
--- a/common_audio/wav_file.cc
+++ b/common_audio/wav_file.cc
@@ -216,32 +216,3 @@
 }
 
 }  // namespace webrtc
-
-rtc_WavWriter* rtc_WavOpen(const char* filename,
-                           int sample_rate,
-                           size_t num_channels) {
-  return reinterpret_cast<rtc_WavWriter*>(
-      new webrtc::WavWriter(filename, sample_rate, num_channels));
-}
-
-void rtc_WavClose(rtc_WavWriter* wf) {
-  delete reinterpret_cast<webrtc::WavWriter*>(wf);
-}
-
-void rtc_WavWriteSamples(rtc_WavWriter* wf,
-                         const float* samples,
-                         size_t num_samples) {
-  reinterpret_cast<webrtc::WavWriter*>(wf)->WriteSamples(samples, num_samples);
-}
-
-int rtc_WavSampleRate(const rtc_WavWriter* wf) {
-  return reinterpret_cast<const webrtc::WavWriter*>(wf)->sample_rate();
-}
-
-size_t rtc_WavNumChannels(const rtc_WavWriter* wf) {
-  return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_channels();
-}
-
-size_t rtc_WavNumSamples(const rtc_WavWriter* wf) {
-  return reinterpret_cast<const webrtc::WavWriter*>(wf)->num_samples();
-}
diff --git a/common_audio/wav_file.h b/common_audio/wav_file.h
index d7aa2c1..1e32bf7 100644
--- a/common_audio/wav_file.h
+++ b/common_audio/wav_file.h
@@ -11,8 +11,6 @@
 #ifndef COMMON_AUDIO_WAV_FILE_H_
 #define COMMON_AUDIO_WAV_FILE_H_
 
-#ifdef __cplusplus
-
 #include <stdint.h>
 #include <cstddef>
 #include <string>
@@ -103,24 +101,4 @@
 
 }  // namespace webrtc
 
-extern "C" {
-#endif  // __cplusplus
-
-// C wrappers for the WavWriter class.
-typedef struct rtc_WavWriter rtc_WavWriter;
-rtc_WavWriter* rtc_WavOpen(const char* filename,
-                           int sample_rate,
-                           size_t num_channels);
-void rtc_WavClose(rtc_WavWriter* wf);
-void rtc_WavWriteSamples(rtc_WavWriter* wf,
-                         const float* samples,
-                         size_t num_samples);
-int rtc_WavSampleRate(const rtc_WavWriter* wf);
-size_t rtc_WavNumChannels(const rtc_WavWriter* wf);
-size_t rtc_WavNumSamples(const rtc_WavWriter* wf);
-
-#ifdef __cplusplus
-}  // extern "C"
-#endif
-
 #endif  // COMMON_AUDIO_WAV_FILE_H_
diff --git a/common_audio/wav_file_unittest.cc b/common_audio/wav_file_unittest.cc
index fef87c8..726552a 100644
--- a/common_audio/wav_file_unittest.cc
+++ b/common_audio/wav_file_unittest.cc
@@ -103,53 +103,6 @@
   }
 }
 
-// Write a tiny WAV file with the C interface and verify the result.
-TEST(WavWriterTest, C) {
-  const std::string outfile = test::OutputPath() + "wavtest2.wav";
-  rtc_WavWriter* w = rtc_WavOpen(outfile.c_str(), 11904, 2);
-  EXPECT_EQ(11904, rtc_WavSampleRate(w));
-  EXPECT_EQ(2u, rtc_WavNumChannels(w));
-  EXPECT_EQ(0u, rtc_WavNumSamples(w));
-  static const size_t kNumSamples = 4;
-  rtc_WavWriteSamples(w, &kSamples[0], 2);
-  EXPECT_EQ(2u, rtc_WavNumSamples(w));
-  rtc_WavWriteSamples(w, &kSamples[2], kNumSamples - 2);
-  EXPECT_EQ(kNumSamples, rtc_WavNumSamples(w));
-  rtc_WavClose(w);
-  static const uint8_t kExpectedContents[] = {
-      // clang-format off
-      // clang formatting doesn't respect inline comments.
-    'R', 'I', 'F', 'F',
-    44, 0, 0, 0,  // size of whole file - 8: 8 + 44 - 8
-    'W', 'A', 'V', 'E',
-    'f', 'm', 't', ' ',
-    16, 0, 0, 0,  // size of fmt block - 8: 24 - 8
-    1, 0,  // format: PCM (1)
-    2, 0,  // channels: 2
-    0x80, 0x2e, 0, 0,  // sample rate: 11904
-    0, 0xba, 0, 0,  // byte rate: 2 * 2 * 11904
-    4, 0,  // block align: NumChannels * BytesPerSample
-    16, 0,  // bits per sample: 2 * 8
-    'd', 'a', 't', 'a',
-    8, 0, 0, 0,  // size of payload: 8
-    0, 0,  // first sample: 0.0
-    10, 0,  // second sample: 10.0
-    0xff, 0x7f,  // third sample: 4e4 (saturated)
-    0, 0x80,  // fourth sample: -1e9 (saturated)
-      // clang-format on
-  };
-  static const size_t kContentSize =
-      kWavHeaderSize + kNumSamples * sizeof(int16_t);
-  static_assert(sizeof(kExpectedContents) == kContentSize, "content size");
-  EXPECT_EQ(kContentSize, test::GetFileSize(outfile));
-  FILE* f = fopen(outfile.c_str(), "rb");
-  ASSERT_TRUE(f);
-  uint8_t contents[kContentSize];
-  ASSERT_EQ(1u, fread(contents, kContentSize, 1, f));
-  EXPECT_EQ(0, fclose(f));
-  EXPECT_EQ(0, memcmp(kExpectedContents, contents, kContentSize));
-}
-
 // Write a larger WAV file. You can listen to this file to sanity-check it.
 TEST(WavWriterTest, LargeFile) {
   std::string outfile = test::OutputPath() + "wavtest3.wav";