Fix Chromium clang plugin warnings

NOTRY=true
BUG=webrtc:163

Review-Url: https://codereview.webrtc.org/2291503002
Cr-Commit-Position: refs/heads/master@{#13959}
diff --git a/webrtc/modules/audio_coding/test/PCMFile.h b/webrtc/modules/audio_coding/test/PCMFile.h
index 840933a..b5ced0b 100644
--- a/webrtc/modules/audio_coding/test/PCMFile.h
+++ b/webrtc/modules/audio_coding/test/PCMFile.h
@@ -26,11 +26,7 @@
  public:
   PCMFile();
   PCMFile(uint32_t timestamp);
-  ~PCMFile() {
-    if (pcm_file_ != NULL) {
-      fclose(pcm_file_);
-    }
-  }
+  ~PCMFile();
 
   void Open(const std::string& filename, uint16_t frequency, const char* mode,
             bool auto_rewind = false);