Fix potential use-after-move in //content/browser/renderer_host/media/

Fix use-after-move (potential) bugs found by the
"bugprone-use-after-move" clang-tidy check.

Bug: 1122844
Change-Id: I2f99b8ecd4118707dc535d15ed3d07c727dce653
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2382078
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Thomas Guilbert <tguilbert@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803190}

content/browser/renderer_host/media/service_video_capture_device_launcher.cc

@@ -155,7 +155,8 @@ void ServiceVideoCaptureDeviceLauncher::LaunchDeviceAsync(
   // in use. In order to be able to set |force_reopen_with_new_settings|, we
   // have to refactor code here and upstream to wait for a callback from the
   // service indicating that the device closing is complete.
-  source->CreatePushSubscription(
+  video_capture::mojom::VideoSource* source_ptr = source.get();
+  source_ptr->CreatePushSubscription(
       std::move(pending_remote_proxy), new_params,
       true /*force_reopen_with_new_settings*/, std::move(subscription_receiver),
       base::BindOnce(