--- a/dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp
+++ b/dom/media/platforms/ffmpeg/FFmpegLibWrapper.cpp
@@ -9,26 +9,16 @@
 #include "mozilla/Types.h"
 #include "prlink.h"
 
 #define AV_LOG_DEBUG    48
 
 namespace mozilla
 {
 
-FFmpegLibWrapper::FFmpegLibWrapper()
-{
-  PodZero(this);
-}
-
-FFmpegLibWrapper::~FFmpegLibWrapper()
-{
-  Unlink();
-}
-
 FFmpegLibWrapper::LinkResult
 FFmpegLibWrapper::Link()
 {
   if (!mAVCodecLib || !mAVUtilLib) {
     Unlink();
     return LinkResult::NoProvidedLib;
   }
 
@@ -170,9 +160,9 @@ FFmpegLibWrapper::Unlink()
     PR_UnloadLibrary(mAVUtilLib);
   }
   if (mAVCodecLib) {
     PR_UnloadLibrary(mAVCodecLib);
   }
   PodZero(this);
 }
 
-} // namespace mozilla
\ No newline at end of file
+} // namespace mozilla

--- a/dom/media/platforms/ffmpeg/FFmpegLibWrapper.h
+++ b/dom/media/platforms/ffmpeg/FFmpegLibWrapper.h
@@ -13,20 +13,25 @@ struct AVFrame;
 struct AVPacket;
 struct AVDictionary;
 struct AVCodecParserContext;
 struct PRLibrary;
 
 namespace mozilla
 {
 
-struct FFmpegLibWrapper
+struct MOZ_ONLY_USED_TO_AVOID_STATIC_CONSTRUCTORS FFmpegLibWrapper
 {
-  FFmpegLibWrapper();
-  ~FFmpegLibWrapper();
+  // The class is used only in static storage and so is zero initialized.
+  FFmpegLibWrapper() = default;
+  // The libraries are not unloaded in the destructor, because doing so would
+  // require a static constructor to register the static destructor.  As the
+  // class is in static storage, the destructor would only run on shutdown
+  // anyway.
+  ~FFmpegLibWrapper() = default;
 
   enum class LinkResult
   {
     Success,
     NoProvidedLib,
     NoAVCodecVersion,
     CannotUseLibAV57,
     BlockedOldLibAVVersion,
@@ -86,9 +91,9 @@ struct FFmpegLibWrapper
   PRLibrary* mAVCodecLib;
   PRLibrary* mAVUtilLib;
 
 private:
 };
 
 } // namespace mozilla
 
-#endif // FFmpegLibWrapper
\ No newline at end of file
+#endif // FFmpegLibWrapper