GitLab

Clean up LayoutSelectionTest output

This patch rewrites test expectation on each Node
with |std::string DumpSelectionInfo()| so that we can check
a SelectionStatus tree with text diff.

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_layout_ng
Change-Id: I337d02e126b6b53efb30c8fd3f16787f4f3c739a
Reviewed-on: https://chromium-review.googlesource.com/1157735Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579694}