Fix VideoDecoderShim to return correct decode_id for all codecs.

media/filters/vpx_video_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/filters/vpx_video_decoder.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 336 matching lines @@
     return;
   }
 
   scoped_refptr<VideoFrame> video_frame;
   if (!VpxDecode(buffer, &video_frame)) {
     state_ = kError;
     base::ResetAndReturn(&decode_cb_).Run(kDecodeError);
     return;
   }
 
-  base::ResetAndReturn(&decode_cb_).Run(kOk);
-
   if (video_frame.get())
     output_cb_.Run(video_frame);
+
+  // VideoDecoderShim expects that |decode_cb| is called only after
+  // |output_cb_|.
+  base::ResetAndReturn(&decode_cb_).Run(kOk);
 }
 
 bool VpxVideoDecoder::VpxDecode(const scoped_refptr<DecoderBuffer>& buffer,
                                 scoped_refptr<VideoFrame>* video_frame) {
   DCHECK(video_frame);
   DCHECK(!buffer->end_of_stream());
 
   // Pass |buffer| to libvpx.
   int64 timestamp = buffer->timestamp().InMicroseconds();
   void* user_priv = reinterpret_cast<void*>(&timestamp);
@@ skipping 131 matching lines @@
         vpx_image->stride[VPX_PLANE_Y], vpx_image->d_h, video_frame->get());
     return;
   }
   CopyAPlane(vpx_image_alpha->planes[VPX_PLANE_Y],
              vpx_image->stride[VPX_PLANE_Y],
              vpx_image->d_h,
              video_frame->get());
 }
 
 }  // namespace media