Added video capture capabilities retrieval and caching to VideoCaptureManager

content/browser/renderer_host/media/video_capture_controller.cc

 // 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 "content/browser/renderer_host/media/video_capture_controller.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
@@ skipping 135 matching lines @@
     base::ProcessHandle render_process,
     const media::VideoCaptureParams& params) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DVLOG(1) << "VideoCaptureController::AddClient, id " << id.device_id
            << ", (" << params.requested_format.width
            << ", " << params.requested_format.height
            << ", " << params.requested_format.frame_rate
            << ", " << params.session_id
            << ")";
 
+  // If this is the first client added to the controller, cache the parameters.
+  if (!controller_clients_.size())
+    video_capture_format_ = params.requested_format;

[perkj_chrome, 2013/11/13 13:04:18]

So adding the first client implies that the capture device is actually started
with this resolution? And does stopping the capture device imply that the
controller is deleted?
Will you still be able to retrieve all capabilities in the render process
media::VideoCapture before you start capturing? 

[no longer working on chromium, 2013/11/13 16:20:22]

curiously, what is this video_capture_format_ cached for?
should this video_capture_format_ be default_video_capture_format_  or
preferred_video_capture_format_?

+
   // Signal error in case device is already in error state.
   if (state_ == VIDEO_CAPTURE_STATE_ERROR) {
     event_handler->OnError(id);
     return;
   }
 
   // Do nothing if this client has called AddClient before.
   if (FindClient(id, event_handler, controller_clients_))
     return;
 
@@ skipping 56 matching lines @@
   // If this buffer is not held by this client, or this client doesn't exist
   // in controller, do nothing.
   if (!client || !client->active_buffers.erase(buffer_id)) {
     NOTREACHED();
     return;
   }
 
   buffer_pool_->RelinquishConsumerHold(buffer_id, 1);
 }
 
+const media::VideoCaptureFormat&
+VideoCaptureController::GetVideoCaptureFormat() const {

[no longer working on chromium, 2013/11/13 16:20:22]

same question on the naming since there might be multiple capture formats.

+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  return video_capture_format_;
+}
+
 scoped_refptr<media::VideoFrame>
 VideoCaptureController::VideoCaptureDeviceClient::ReserveOutputBuffer(
     const gfx::Size& size) {
   return DoReserveI420VideoFrame(size, 0);
 }
 
 void VideoCaptureController::VideoCaptureDeviceClient::OnIncomingCapturedFrame(
     const uint8* data,
     int length,
     base::Time timestamp,
@@ skipping 316 matching lines @@
   }
   return NULL;
 }
 
 int VideoCaptureController::GetClientCount() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   return controller_clients_.size();
 }
 
 }  // namespace content