getUserMeida: report device starting states

media/capture/video/linux/v4l2_capture_delegate.cc

 // Copyright 2015 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/capture/video/linux/v4l2_capture_delegate.h"
 
 #include <linux/version.h>
 #include <linux/videodev2.h>
 #include <poll.h>
 #include <sys/fcntl.h>
@@ skipping 453 matching lines @@
     }
   }
 
   v4l2_buf_type capture_type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_STREAMON, &capture_type)) <
       0) {
     SetErrorState(FROM_HERE, "VIDIOC_STREAMON failed");
     return;
   }
 
+  client_->OnStarted();
   is_capturing_ = true;
+
   // Post task to start fetching frames from v4l2.
   v4l2_task_runner_->PostTask(
       FROM_HERE, base::Bind(&V4L2CaptureDelegate::DoCapture, this));
 }
 
 void V4L2CaptureDelegate::StopAndDeAllocate() {
   DCHECK(v4l2_task_runner_->BelongsToCurrentThread());
   // The order is important: stop streaming, clear |buffer_pool_|,
   // thus munmap()ing the v4l2_buffers, and then return them to the OS.
   v4l2_buf_type capture_type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
@@ skipping 301 matching lines @@
     DLOG(ERROR) << "Error mmap()ing a V4L2 buffer into userspace";
     return false;
   }
   start_ = static_cast<uint8_t*>(start);
   length_ = buffer.length;
   payload_size_ = 0;
   return true;
 }
 
 }  // namespace media