DevTools: Do not re-enter WebInspector.PanelDescriptor.panel() method from sources panel constructor

R=pfeldman

Review URL: https://codereview.chromium.org/51953008

git-svn-id: svn://svn.chromium.org/blink/trunk@161070 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: remove gutter from overlay page.

BUG=305633

Review URL: https://codereview.chromium.org/53613003

git-svn-id: svn://svn.chromium.org/blink/trunk@161071 bbb929c8-8fbe-4397-9dbb-9b2b20218538