Auto-rebaseline for r182920

http://src.chromium.org/viewvc/blink?view=revision&revision=182920

BUG=334269
TBR=dominik.rottsches@intel.com

Review URL: https://codereview.chromium.org/618853003

git-svn-id: svn://svn.chromium.org/blink/trunk@182963 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [Sources] do not retain errors in sources between navigations

As per today, if the UISourceCode remains between navigations and the
"preserve log between navigations" setting is enabled, then errors
are accumulated in the sources for ever.
Is is undesirable behavior; in fact, we'd like to show errors in the
source code since only the last navigation.

This patch resets all the messages from javascript source whenever
the global object gets cleared.

BUG=331220
R=vsevik, pfeldman

Review URL: https://codereview.chromium.org/612513005

git-svn-id: svn://svn.chromium.org/blink/trunk@182964 bbb929c8-8fbe-4397-9dbb-9b2b20218538