Revert 41386 - Removed custom FFmpegLock. Removed ffmpeg headers from third_p...

media/filters/ffmpeg_demuxer.cc

Index: media/filters/ffmpeg_demuxer.cc
===================================================================
--- media/filters/ffmpeg_demuxer.cc	(revision 41387)
+++ media/filters/ffmpeg_demuxer.cc	(working copy)
@@ -235,6 +235,7 @@
   // in the decoder filters. By reaching this point, all filters should have
   // stopped, so this is the only safe place to do the global clean up.
   // TODO(hclam): close the codecs in the corresponding decoders.
+  AutoLock auto_lock(FFmpegLock::get()->lock());
   if (!format_context_)
     return;
 
@@ -396,12 +397,17 @@
   DCHECK(context);
   format_context_ = context;
 
-  // Fully initialize AVFormatContext by parsing the stream a little.
-  result = av_find_stream_info(format_context_);
-  if (result < 0) {
-    host()->SetError(DEMUXER_ERROR_COULD_NOT_PARSE);
-    callback->Run();
-    return;
+  // Serialize calls to av_find_stream_info().
+  {
+    AutoLock auto_lock(FFmpegLock::get()->lock());
+
+    // Fully initialize AVFormatContext by parsing the stream a little.
+    result = av_find_stream_info(format_context_);
+    if (result < 0) {
+      host()->SetError(DEMUXER_ERROR_COULD_NOT_PARSE);
+      callback->Run();
+      return;
+    }
   }
 
   // Create demuxer streams for all supported streams.