Rename a directory, files, and class names in content/shell/renderer/layout_test

For "Web Test".

This CL has no behavior changes.

Bug: 843412
Change-Id: Ic3cf211efc420f07528df5fcfd9193f08f99dcf0
Reviewed-on: https://chromium-review.googlesource.com/c/1353068
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612100}
23 files changed