DevTools: render time summary as a pie chart on Timeline panel.
Drive by: remove pid comparison from TimelinePanel.js - it does not belong there.

Review URL: https://codereview.chromium.org/77043006

git-svn-id: svn://svn.chromium.org/blink/trunk@162503 bbb929c8-8fbe-4397-9dbb-9b2b20218538