getUserMeida: report device starting states

media/capture/video/mac/video_capture_device_mac.mm

 // 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/capture/video/mac/video_capture_device_mac.h"
 
 #include <IOKit/IOCFPlugIn.h>
 #include <IOKit/usb/IOUSBLib.h>
 #include <IOKit/usb/USBSpec.h>
 #include <stddef.h>
@@ skipping 342 matching lines @@
                                 GetPowerLineFrequency(params));
     }
   }
 
   if (![capture_device_ startCapture]) {
     SetErrorState(FROM_HERE, "Could not start capture device.");
     return;
   }
 
   state_ = kCapturing;
+  client_->OnStarted();
 }
 
 void VideoCaptureDeviceMac::StopAndDeAllocate() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(state_ == kCapturing || state_ == kError) << state_;
 
   [capture_device_ setCaptureDevice:nil];
   [capture_device_ setFrameReceiver:nil];
   client_.reset();
   state_ = kIdle;
@@ skipping 115 matching lines @@
   if (![capture_device_ setCaptureHeight:capture_format_.frame_size.height()
                                    width:capture_format_.frame_size.width()
                                frameRate:capture_format_.frame_rate]) {
     ReceiveError(FROM_HERE, "Could not configure capture device.");
     return false;
   }
   return true;
 }
 
 }  // namespace media