Add OWNERS to c/b/ui/qrcode_generator

Matches c/b/ui/views/qrcode_generator

Change-Id: I4e2a0600908b849893decdd0b0d72162d55ce5fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2227853
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#774632}

chrome/browser/ui/qrcode_generator/OWNERS

+file://components/send_tab_to_self/OWNERS
+
+# COMPONENT: UI>Browser>Sharing