[Invalidation tracking] Add trace events for layout invalidations

This patch adds trace events for setNeedsLayout calls so that we can
do end-to-end tracking of what causes repaints to occur. The devtools
side isn't yet hooked up so this patch simply adds the trace event.

As a cleanup, "core/inspector/InspectorTraceEvents.h" has been moved
up into RenderObject and unneeded includes have been removed.

R=kouhei
BUG=410701

Review URL: https://codereview.chromium.org/561413002

git-svn-id: svn://svn.chromium.org/blink/trunk@181865 bbb929c8-8fbe-4397-9dbb-9b2b20218538