DevTools: Improve animated highlighting in the Network and Profiler panels

R=eustas, loislo
BUG=341146

Review URL: https://codereview.chromium.org/142173003

git-svn-id: svn://svn.chromium.org/blink/trunk@166618 bbb929c8-8fbe-4397-9dbb-9b2b20218538