Handle config change during pending reset correctly in FFmpegVideoDecoder.

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 6f6c49506d54ebe41f26fd474d913bdbd67c202a..a0991f3635bd5317cd0f7cbdda77a09f293ee7df 100644
--- a/media/filters/ffmpeg_video_decoder.cc
+++ b/media/filters/ffmpeg_video_decoder.cc
@@ -233,6 +233,25 @@ void FFmpegVideoDecoder::BufferReady(
 
   DCHECK(!read_cb_.is_null());
 
+  if (status == DemuxerStream::kConfigChanged) {
+    if (!ConfigureDecoder()) {
+      base::ResetAndReturn(&read_cb_).Run(kDecodeError, NULL);
+      state_ = kDecodeFinished;

[acolwell GONE FROM CHROMIUM, 2013/01/03 17:53:31]

Why is this needed now? The Read() shouldn't be called again after kDecodeError
is returned. If anything we should transition to a state that always returns
kDecodeError for all future Read() calls until a Reset() happens.

[xhwang, 2013/01/04 01:28:05]

This transition follows the comment on line 298. I agree that kDecodeFinished
may not be the best option. But that'd be in another CL.

+      if (!reset_cb_.is_null())
+        base::ResetAndReturn(&reset_cb_).Run();
+      return;
+    }
+
+    if (!reset_cb_.is_null()) {

[acolwell GONE FROM CHROMIUM, 2013/01/03 17:53:31]

nit: If you flip the condition here you can reuse the DoReset() code below
instead of duplicating it here.

[xhwang, 2013/01/04 01:28:05]

Done.

+      base::ResetAndReturn(&read_cb_).Run(kOk, NULL);
+      DoReset();
+      return;
+    }
+
+    ReadFromDemuxerStream();
+    return;
+  }
+
   if (!reset_cb_.is_null()) {
     base::ResetAndReturn(&read_cb_).Run(kOk, NULL);
     DoReset();
@@ -244,16 +263,6 @@ void FFmpegVideoDecoder::BufferReady(
     return;
   }
 
-  if (status == DemuxerStream::kConfigChanged) {
-    if (!ConfigureDecoder()) {
-      base::ResetAndReturn(&read_cb_).Run(kDecodeError, NULL);
-      return;
-    }
-
-    ReadFromDemuxerStream();
-    return;
-  }
-
   DCHECK_EQ(status, DemuxerStream::kOk);
   DecodeBuffer(buffer);
 }