DevTools: Use scriptId for resolving stack frames in console messages

BUG=272742
R=yurys@chromium.org, pfeldman@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23717011

git-svn-id: svn://svn.chromium.org/blink/trunk@157129 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Do not flood console with 404 messages on failed source map load attempts.

R=pfeldman, paulirish@chromium.org
BUG=283903

Review URL: https://chromiumcodereview.appspot.com/23719009

git-svn-id: svn://svn.chromium.org/blink/trunk@157130 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: polish screencast view (add checkerboard backgroundi, beautify border size and color).

Review URL: https://chromiumcodereview.appspot.com/23604031

git-svn-id: svn://svn.chromium.org/blink/trunk@157131 bbb929c8-8fbe-4397-9dbb-9b2b20218538