[Fuchsia] Add VideoCaptureDeviceFactory stub

VideoCaptureSystemImpl expects to have non-null
VideoCaptureDeviceFactory, but it was getting nullptr value on Fuchsia.
As result the browser was crashing

Bug: 866669
Change-Id: I73ec5c850acdc392a7984f62d9f66edb0961809a
Reviewed-on: https://chromium-review.googlesource.com/1147514
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Christian Fremerey <chfremer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577415}

media/capture/BUILD.gn

@@ -270,6 +270,13 @@ component("capture_lib") {
       "//third_party/libsync",
     ]
   }
+
+  if (is_fuchsia) {
+    sources += [
+      "video/fuchsia/video_capture_device_factory_fuchsia.cc",
+      "video/fuchsia/video_capture_device_factory_fuchsia.h",
+    ]
+  }
 }
 
 source_set("test_support") {

media/capture/video/create_video_capture_device_factory.cc

@@ -22,6 +22,8 @@
 #include "media/capture/video/mac/video_capture_device_factory_mac.h"
 #elif defined(OS_ANDROID)
 #include "media/capture/video/android/video_capture_device_factory_android.h"
+#elif defined(OS_FUCHSIA)
+#include "media/capture/video/fuchsia/video_capture_device_factory_fuchsia.h"
 #endif
 
 namespace media {
@@ -54,6 +56,8 @@ CreatePlatformSpecificVideoCaptureDeviceFactory(
   return std::make_unique<VideoCaptureDeviceFactoryMac>();
 #elif defined(OS_ANDROID)
   return std::make_unique<VideoCaptureDeviceFactoryAndroid>();
+#elif defined(OS_FUCHSIA)
+  return std::make_unique<VideoCaptureDeviceFactoryFuchsia>();
 #else
   NOTIMPLEMENTED();
   return nullptr;

media/capture/video/fuchsia/video_capture_device_factory_fuchsia.cc

+// Copyright 2018 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/fuchsia/video_capture_device_factory_fuchsia.h"
+
+#include "base/logging.h"
+
+namespace media {
+
+VideoCaptureDeviceFactoryFuchsia::VideoCaptureDeviceFactoryFuchsia() = default;
+VideoCaptureDeviceFactoryFuchsia::~VideoCaptureDeviceFactoryFuchsia() = default;
+
+std::unique_ptr<VideoCaptureDevice>
+VideoCaptureDeviceFactoryFuchsia::CreateDevice(
+    const VideoCaptureDeviceDescriptor& device_descriptor) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+void VideoCaptureDeviceFactoryFuchsia::GetDeviceDescriptors(
+    VideoCaptureDeviceDescriptors* device_descriptors) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  device_descriptors->clear();
+}
+
+void VideoCaptureDeviceFactoryFuchsia::GetSupportedFormats(
+    const VideoCaptureDeviceDescriptor& device,
+    VideoCaptureFormats* capture_formats) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  capture_formats->clear();
+}
+
+}  // namespace media

media/capture/video/fuchsia/video_capture_device_factory_fuchsia.h

+// Copyright 2018 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.
+
+#ifndef MEDIA_CAPTURE_VIDEO_FUCHSIA_VIDEO_CAPTURE_DEVICE_FACTORY_FUCHSIA_H_
+#define MEDIA_CAPTURE_VIDEO_FUCHSIA_VIDEO_CAPTURE_DEVICE_FACTORY_FUCHSIA_H_
+
+#include "media/capture/video/video_capture_device_factory.h"
+
+namespace media {
+
+class CAPTURE_EXPORT VideoCaptureDeviceFactoryFuchsia
+    : public VideoCaptureDeviceFactory {
+ public:
+  VideoCaptureDeviceFactoryFuchsia();
+  ~VideoCaptureDeviceFactoryFuchsia() override;
+
+  std::unique_ptr<VideoCaptureDevice> CreateDevice(
+      const VideoCaptureDeviceDescriptor& device_descriptor) override;
+  void GetDeviceDescriptors(
+      VideoCaptureDeviceDescriptors* device_descriptors) override;
+  void GetSupportedFormats(const VideoCaptureDeviceDescriptor& device,
+                           VideoCaptureFormats* supported_formats) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceFactoryFuchsia);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_CAPTURE_VIDEO_FUCHSIA_VIDEO_CAPTURE_DEVICE_FACTORY_FUCHSIA_H_

services/video_capture/device_factory_provider_impl.cc

@@ -113,6 +113,8 @@ void DeviceFactoryProviderImpl::LazyInitializeDeviceFactory() {
   std::unique_ptr<media::VideoCaptureDeviceFactory> media_device_factory =
       media::CreateVideoCaptureDeviceFactory(
           base::ThreadTaskRunnerHandle::Get());
+  DCHECK(media_device_factory);
+
   auto video_capture_system = std::make_unique<media::VideoCaptureSystemImpl>(
       std::move(media_device_factory));