Fix C++/Python symbols related to "layout test" in blink/renderer

Bug: 843412
Change-Id: I5f5b67cbefe1fa6f591a62cd646b0babacbe4a4f
Reviewed-on: https://chromium-review.googlesource.com/c/1371309
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615760}
7 files changed