DevTools: [CodeMirror] fix indentation bug

Fix indentation bug in CodeMirrorTextEditor. The bug
was caused by the fact that "function foo() {".substr(0 - 1, 1) returns
"{".

BUG=256231

Review URL: https://chromiumcodereview.appspot.com/18332006

git-svn-id: svn://svn.chromium.org/blink/trunk@153350 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Reland "Remove our logic to handle stopping a load inside startProvisionaLoad callbacks"

This reverts commit 5c418ddb584ec86e340626e8140ef04d0eb5e5fc.

BUG=

Review URL: https://chromiumcodereview.appspot.com/18153008

git-svn-id: svn://svn.chromium.org/blink/trunk@153351 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: [CodeMirror] add listener for indentation setting

This patch adds listener so that CodeMirrorTextEditor
will react on indentation setting change without
devtools reloading.

BUG=

Review URL: https://chromiumcodereview.appspot.com/18362003

git-svn-id: svn://svn.chromium.org/blink/trunk@153352 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Added console line on top, showing that some console messages are hidden due to filters.

BUG=255455

Review URL: https://chromiumcodereview.appspot.com/18120008

git-svn-id: svn://svn.chromium.org/blink/trunk@153353 bbb929c8-8fbe-4397-9dbb-9b2b20218538