DevTools: [regressions r173512] can't select entry on timeline flame; frame mode is broken.

TBR=yurys
BUG=372189

Review URL: https://codereview.chromium.org/274353002

git-svn-id: svn://svn.chromium.org/blink/trunk@173833 bbb929c8-8fbe-4397-9dbb-9b2b20218538