Timeline: show record details as a tabbed pane

This changes TimelineDetailsView to be a TabbedPane and lets us add
additional tabs for record types where we can show more details (e.g.
layer tree view or paint profiler). The old details remain in "default"
first tab. Also, for selected range stats, we now show range begin-end
as a part of details view, not in the header.

BUG=

Review URL: https://codereview.chromium.org/325313006

git-svn-id: svn://svn.chromium.org/blink/trunk@176414 bbb929c8-8fbe-4397-9dbb-9b2b20218538