Let Contraints Controll Mute/Unmute Audio Local Playback For Desktop Sharing

content/browser/media/capture/web_contents_video_capture_device.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.
 //
 // Implementation notes: This needs to work on a variety of hardware
 // configurations where the speed of the CPU and GPU greatly affect overall
 // performance. Spanning several threads, the process of capturing has been
 // split up into four conceptual stages:
 //
 //   1. Reserve Buffer: Before a frame can be captured, a slot in the client's
@@ skipping 935 matching lines @@
                                             enable_auto_throttling)))) {}
 
 WebContentsVideoCaptureDevice::~WebContentsVideoCaptureDevice() {
   DVLOG(2) << "WebContentsVideoCaptureDevice@" << this << " destroying.";
 }
 
 // static
 media::VideoCaptureDevice* WebContentsVideoCaptureDevice::Create(
     const std::string& device_id) {
   // Parse device_id into render_process_id and main_render_frame_id.
-  int render_process_id = -1;
-  int main_render_frame_id = -1;
-  if (!WebContentsMediaCaptureId::ExtractTabCaptureTarget(
-          device_id, &render_process_id, &main_render_frame_id)) {
+  WebContentsMediaCaptureId media_id;
+  if (!WebContentsMediaCaptureId::Parse(device_id, &media_id)) {
     return NULL;
   }
 
-  return new WebContentsVideoCaptureDevice(
-      render_process_id, main_render_frame_id,
-      WebContentsMediaCaptureId::IsAutoThrottlingOptionSet(device_id));
+  return new WebContentsVideoCaptureDevice(media_id.render_process_id,
+                                           media_id.main_render_frame_id,
+                                           media_id.enable_auto_throttling);

[Avi (use Gerrit), 2016/09/22 18:19:36]

If you return a new object, make it return a std::unique_ptr to enforce that the
caller must take ownership.

We have been lazy in this regard in the past, and we must step up and do the
right thing here. Please fix this, and make sure that in all future CLs you
properly return unique_ptrs when returning new objects.

[qiangchen, 2016/09/22 20:40:59]

Done.

 }
 
 void WebContentsVideoCaptureDevice::AllocateAndStart(
     const media::VideoCaptureParams& params,
     std::unique_ptr<Client> client) {
   DVLOG(1) << "Allocating " << params.requested_format.frame_size.ToString();
   core_->AllocateAndStart(params, std::move(client));
 }
 
 void WebContentsVideoCaptureDevice::RequestRefreshFrame() {
   core_->RequestRefreshFrame();
 }
 
 void WebContentsVideoCaptureDevice::StopAndDeAllocate() {
   core_->StopAndDeAllocate();
 }
 
 }  // namespace content