Adding showing scroll rects for layers.

Review URL: https://codereview.chromium.org/238923002

Review URL: https://codereview.chromium.org/238923002

git-svn-id: svn://svn.chromium.org/blink/trunk@171575 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Make compiler output shorter, remove some unneeded new lines.

R=apavlov@chromium.org, apavlov, pfeldman

Review URL: https://codereview.chromium.org/235863019

git-svn-id: svn://svn.chromium.org/blink/trunk@171576 bbb929c8-8fbe-4397-9dbb-9b2b20218538