Fix DCHECKs in V4l2VideoDevice.

content/common/gpu/media/v4l2_video_encode_accelerator.cc

 // Copyright 2014 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 <fcntl.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/eventfd.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ skipping 842 matching lines @@
   size_t adjusted_output_buffer_size =
       base::checked_cast<size_t>(format.fmt.pix_mp.plane_fmt[0].sizeimage);
   DCHECK_GE(adjusted_output_buffer_size, output_buffer_byte_size_);
   output_buffer_byte_size_ = adjusted_output_buffer_size;
 
   return true;
 }
 
 bool V4L2VideoEncodeAccelerator::NegotiateInputFormat(
     media::VideoFrame::Format input_format) {
+  DVLOG(3) << "NegotiateInputFormat()";
   DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
   DCHECK(!input_streamon_);
   DCHECK(!output_streamon_);
 
   device_input_format_ = media::VideoFrame::UNKNOWN;
   input_planes_count_ = 0;
 
   uint32 input_format_fourcc =
       V4L2Device::VideoFrameFormatToV4L2PixFmt(input_format);
   if (!input_format_fourcc) {
@@ skipping 216 matching lines @@
   reqbufs.count = 0;
   reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
   reqbufs.memory = V4L2_MEMORY_MMAP;
   IOCTL_OR_LOG_ERROR(VIDIOC_REQBUFS, &reqbufs);
 
   output_buffer_map_.clear();
   free_output_buffers_.clear();
 }
 
 }  // namespace content