DevTools: Show JS call stacks on timeline.

BUG=363976

Review URL: https://codereview.chromium.org/244893002

git-svn-id: svn://svn.chromium.org/blink/trunk@172034 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [Console] refactor method updateMessageList to avoid traversing DOM

This patch updates method ConsoleView.updateMessageList to avoid traversing DOM
structure of ConsoleMessages. All calls to insert/remove messages
are sent to the owning ConsoleGroup, thus making ConsoleGroup solely responsible
for the DOM structure of its console messages.

Review URL: https://codereview.chromium.org/243023002

git-svn-id: svn://svn.chromium.org/blink/trunk@172035 bbb929c8-8fbe-4397-9dbb-9b2b20218538