GitLab

When obtaining initial focus when a webview becomes visible,
ensure that the contained web contents within a webview are valid
before attempting to focus it.

Bug: internal b/173633818
Test: manual
Change-Id: I7abec0ca2ccf4d4a804fbafc3c630d0def7ce242
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2550161
Commit-Queue: Ryan Daum <rdaum@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829276}