DevTools: [CodeMirror] fix popover
DevTools: [CodeMirror] fix popover

This patch fixes the regression which completely broke popover so that
it doesn't show up anymore. The regression was caused by r153329.

BUG=
R=apavlov@chromium.org

Review URL: https://codereview.chromium.org/18504002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@153410 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs