Clarify resolution change behaviors of video capture devices

content/renderer/media/media_stream_video_capturer_source.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 "content/renderer/media/media_stream_video_capturer_source.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "content/renderer/media/video_capture_impl_manager.h"
@@ skipping 219 matching lines @@
       callback);
 }
 
 void MediaStreamVideoCapturerSource::StartSourceImpl(
     const media::VideoCaptureFormat& format,
     const VideoCaptureDeliverFrameCB& frame_callback) {
   media::VideoCaptureParams new_params;
   new_params.requested_format = format;
   if (device_info().device.type == MEDIA_TAB_VIDEO_CAPTURE ||
       device_info().device.type == MEDIA_DESKTOP_VIDEO_CAPTURE) {
-    new_params.allow_resolution_change = true;
+    new_params.resolution_change_policy =
+        media::RESOLUTION_POLICY_DYNAMIC_WITHIN_LIMIT;
   }
   delegate_->StartCapture(
       new_params,
       frame_callback,
       base::Bind(&MediaStreamVideoCapturerSource::OnStartDone,
                  base::Unretained(this)));
 }
 
 void MediaStreamVideoCapturerSource::StopSourceImpl() {
   delegate_->StopCapture();
 }
 
 }  // namespace content