Fix ChunkDemuxer seek deadlock

media/filters/ffmpeg_video_decoder.cc

Index: media/filters/ffmpeg_video_decoder.cc
diff --git a/media/filters/ffmpeg_video_decoder.cc b/media/filters/ffmpeg_video_decoder.cc
index 048cbe517a5ed7d7d29cf911fef47486532de979..67904e0b0f49a5d4c2f97019a5ced2b49ed326ef 100644
--- a/media/filters/ffmpeg_video_decoder.cc
+++ b/media/filters/ffmpeg_video_decoder.cc
@@ -29,7 +29,7 @@ namespace media {
 // decoding thread, FFmpeg treats having one thread the same as having zero
 // threads (i.e., avcodec_decode_video() will execute on the calling thread).
 // Yet another reason for having two threads :)
-static const int kDecodeThreads = 2;
+static const int kDecodeThreads = 1;

[Ami GONE FROM CHROMIUM, 2012/01/27 23:44:58]

??

[acolwell GONE FROM CHROMIUM, 2012/01/29 03:00:41]

This was to temporarily make valgrind shutup about FFVP8. I've reverted this
change for now. Fixing valgrind issues is the next thing on my list
(http://crbug.com/109875).

 static const int kMaxDecodeThreads = 16;
 
 // Returns the number of threads given the FFmpeg CodecID. Also inspects the
@@ -221,6 +221,11 @@ void FFmpegVideoDecoder::DoDecodeBuffer(const scoped_refptr<Buffer>& buffer) {
   DCHECK_NE(state_, kDecodeFinished);
   DCHECK(!read_cb_.is_null());
 
+  if (!buffer) {

[Ami GONE FROM CHROMIUM, 2012/01/27 23:44:58]

GpuVideoDecoder::RequestBufferDecode needs to similarly change?

[acolwell GONE FROM CHROMIUM, 2012/01/29 03:00:41]

Done.

+    DeliverFrame(NULL);
+    return;
+  }
+
   // During decode, because reads are issued asynchronously, it is possible to
   // receive multiple end of stream buffers since each read is acked. When the
   // first end of stream buffer is read, FFmpeg may still have frames queued