media: add video capture device for ARC++ camera HAL v3

media/capture/video/chromeos/video_capture_device_factory_chromeos.cc

+// Copyright 2017 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/chromeos/video_capture_device_factory_chromeos.h"
+
+namespace media {
+
+VideoCaptureDeviceFactoryChromeOS::VideoCaptureDeviceFactoryChromeOS(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner)
+    : ui_task_runner_(ui_task_runner), module_thread_("CameraModuleThread") {}
+
+VideoCaptureDeviceFactoryChromeOS::~VideoCaptureDeviceFactoryChromeOS() {}
+
+bool VideoCaptureDeviceFactoryChromeOS::Init() {

[chfremer, 2017/04/26 21:13:05]

Add DCHECK(thread_checker_.CalledOnValidThread());?

[jcliang, 2017/04/27 07:07:57]

Init is called on the browser IO thread when we create the factory instance.

I should add a comment to make this clear.

+  if (!module_thread_.Start()) {
+    LOG(ERROR) << "Module thread failed to start";
+    return false;
+  }
+  camera_hal_delegate_ = new CameraHalDelegate(module_thread_.task_runner());
+  return camera_hal_delegate_->StartCameraModuleIpc();
+}
+
+std::unique_ptr<VideoCaptureDevice>
+VideoCaptureDeviceFactoryChromeOS::CreateDevice(
+    const VideoCaptureDeviceDescriptor& device_descriptor) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return camera_hal_delegate_->CreateDevice(ui_task_runner_, device_descriptor);
+}
+
+void VideoCaptureDeviceFactoryChromeOS::GetSupportedFormats(
+    const VideoCaptureDeviceDescriptor& device_descriptor,
+    VideoCaptureFormats* supported_formats) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  camera_hal_delegate_->GetSupportedFormats(device_descriptor,
+                                            supported_formats);
+}
+
+void VideoCaptureDeviceFactoryChromeOS::GetDeviceDescriptors(
+    VideoCaptureDeviceDescriptors* device_descriptors) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  camera_hal_delegate_->GetDeviceDescriptors(device_descriptors);
+}
+
+#if defined(OS_CHROMEOS)
+// static
+VideoCaptureDeviceFactory*
+VideoCaptureDeviceFactory::CreateVideoCaptureDeviceFactory(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
+  std::unique_ptr<VideoCaptureDeviceFactoryChromeOS> factory(
+      new VideoCaptureDeviceFactoryChromeOS(ui_task_runner));
+  if (!factory->Init()) {
+    return nullptr;
+  }
+  return factory.release();
+}
+#endif
+
+}  // namespace media