media/gpu/v4l2vd: remove incorrect DCHECK()

ContinueChangeResolution() had a DCHECK() that made sure that no CAPTURE
buffers were queued when the method was called. This is incorrect ;
especially for stateful decoders where we passively queue all CAPTURE
buffers as they become available, and can also happen with stateless
decoders as well.

BUG=b:168193954
TEST=video.DecodeAccelVD.h264_resolution_switch does not raise this
trigger anymore on hana-kernelnext.

Change-Id: Ia86e99e59a1665fe21f7c21eccee36c75840d0db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2405346
Auto-Submit: Alexandre Courbot <acourbot@chromium.org>
Commit-Queue: Chih-Yu Huang <akahuang@chromium.org>
Reviewed-by: Chih-Yu Huang <akahuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806147}

media/gpu/v4l2/v4l2_video_decoder.cc

@@ -500,7 +500,6 @@ void V4L2VideoDecoder::ContinueChangeResolution(
     const size_t num_output_frames) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(decoder_sequence_checker_);
   DVLOGF(3);
-  DCHECK_EQ(output_queue_->QueuedBuffersCount(), 0u);
 
   // If we already reset, then skip it.
   if (state_ == State::kDecoding)