[Mojo Video Capture] Hook up video capture service behind a feature flag

content/browser/renderer_host/media/media_stream_manager.cc

Index: content/browser/renderer_host/media/media_stream_manager.cc
diff --git a/content/browser/renderer_host/media/media_stream_manager.cc b/content/browser/renderer_host/media/media_stream_manager.cc
index 5818cef620e58357d7f789e52d61c7e64d4cb19e..15e32c1eedf0f384517d0813349c17c20f8316bb 100644
--- a/content/browser/renderer_host/media/media_stream_manager.cc
+++ b/content/browser/renderer_host/media/media_stream_manager.cc
@@ -33,7 +33,9 @@
 #include "content/browser/renderer_host/media/media_devices_manager.h"
 #include "content/browser/renderer_host/media/media_stream_requester.h"
 #include "content/browser/renderer_host/media/media_stream_ui_proxy.h"
+#include "content/browser/renderer_host/media/service_video_capture_provider.h"
 #include "content/browser/renderer_host/media/video_capture_manager.h"
+#include "content/browser/renderer_host/media/video_capture_provider_switcher.h"
 #include "content/browser/renderer_host/render_process_host_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
@@ -52,6 +54,7 @@
 #include "media/base/media_switches.h"
 #include "media/capture/video/video_capture_device_factory.h"
 #include "media/capture/video/video_capture_system_impl.h"
+#include "services/video_capture/public/cpp/constants.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
@@ -423,6 +426,11 @@ MediaStreamManager::MediaStreamManager(
             media::VideoCaptureDeviceFactory::CreateFactory(
                 BrowserThread::GetTaskRunnerForThread(BrowserThread::UI))),
         std::move(device_task_runner));
+    if (base::FeatureList::IsEnabled(video_capture::kMojoVideoCapture)) {
+      video_capture_provider = base::MakeUnique<VideoCaptureProviderSwitcher>(
+          base::MakeUnique<ServiceVideoCaptureProvider>(),
+          std::move(video_capture_provider));
+    }
   }
   InitializeMaybeAsync(std::move(video_capture_provider));