DebugVisualizers: Blink rename to Chromium style and a few additions

This patch changes DebugVisuzlizers files to support Blink rename to
Chromium style.

Also adds following classes:
* base::Optional
* blink::MemberBase
* blink::PersistentBase
* Several basic classes for LayoutNG

Review-Url: https://codereview.chromium.org/2809043007
Cr-Original-Commit-Position: refs/heads/master@{#465104}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 96f54215dca792081a50085f78cb9cdbdcf157d4
2 files changed