ContentCapture: Provide a way for subclass to create ContentCaptureConsumer

Bug: 924681
Change-Id: I4ec1dabaa39cfe875a76030ab717c3b371afcc88
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1621307
Commit-Queue: Tao Bai <michaelbai@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662711}
1 file changed