This is already a heap root, so no need to internalize the string again,
nor to open a local handle for it (the one the factory gives is sufficient).

Change-Id: I5095bd378956ab6667b8a1f9d8f3e3d19ddffdb9
Reviewed-on: https://chromium-review.googlesource.com/1177889Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Jeremy Roman <jbroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55216}