Rmoving the notion of task runner from MediaStreamProvider interface.

content/browser/renderer_host/media/video_capture_manager.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_manager.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 
@@ skipping 309 matching lines @@
     int serial_id,
     media::VideoCaptureSessionId session_id,
     const media::VideoCaptureParams& params)
     : serial_id_(serial_id),
       session_id_(session_id),
       params_(params),
       abort_start_(false) {
 }
 
 VideoCaptureManager::VideoCaptureManager(
-    std::unique_ptr<media::VideoCaptureDeviceFactory> factory)
-    : listener_(nullptr),
+    std::unique_ptr<media::VideoCaptureDeviceFactory> factory,
+    scoped_refptr<base::SingleThreadTaskRunner> device_task_runner)
+    : device_task_runner_(std::move(device_task_runner)),
+      listener_(nullptr),
       new_capture_session_id_(1),
       video_capture_device_factory_(std::move(factory)) {}
 
 VideoCaptureManager::~VideoCaptureManager() {
   DCHECK(devices_.empty());
   DCHECK(device_start_queue_.empty());
 }
 
-void VideoCaptureManager::Register(
-    MediaStreamProviderListener* listener,
-    const scoped_refptr<base::SingleThreadTaskRunner>& device_task_runner) {
+void VideoCaptureManager::RegisterListener(
+    MediaStreamProviderListener* listener) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(!listener_);
-  DCHECK(!device_task_runner_.get());
+  DCHECK(device_task_runner_);
   listener_ = listener;
-  device_task_runner_ = device_task_runner;
 #if defined(OS_ANDROID)
   application_state_has_running_activities_ = true;
   app_status_listener_.reset(new base::android::ApplicationStatusListener(
       base::Bind(&VideoCaptureManager::OnApplicationStateChange,
                  base::Unretained(this))));
 #endif
 }
 
-void VideoCaptureManager::Unregister() {
+void VideoCaptureManager::UnregisterListener() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(listener_);
   listener_ = nullptr;
 }
 
 void VideoCaptureManager::EnumerateDevices(
     const EnumerationCallback& client_callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DVLOG(1) << "VideoCaptureManager::EnumerateDevices";
 
   // Bind a callback to ConsolidateDevicesInfoOnDeviceThread() with an argument
@@ skipping 982 matching lines @@
     if (!device_in_queue) {
       // Session ID is only valid for Screen capture. So we can fake it to
       // resume video capture devices here.
       QueueStartDevice(kFakeSessionId, entry.get(), entry->parameters);
     }
   }
 }
 #endif  // defined(OS_ANDROID)
 
 }  // namespace content