DevTools: fix cursor icon over the chevron in tabbed pane

The chevron icon currently inherits the cursor style from its parent,
which is incorrect.

BUG=440329
R=vsevik
NOTRY=true

Review URL: https://codereview.chromium.org/812583002

git-svn-id: svn://svn.chromium.org/blink/trunk@187254 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: remove documentation experiment along with the code.

Review URL: https://codereview.chromium.org/804793003

git-svn-id: svn://svn.chromium.org/blink/trunk@187255 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: CustomFormatters via jsonML

Formatter example: http://pastebin.com/FR2jfbxk

BUG=

Review URL: https://codereview.chromium.org/774903003

git-svn-id: svn://svn.chromium.org/blink/trunk@187256 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Move extra annotation parameters from Runner to the python script

BUG=
R=apavlov@chromium.org

Review URL: https://codereview.chromium.org/799273004

git-svn-id: svn://svn.chromium.org/blink/trunk@187257 bbb929c8-8fbe-4397-9dbb-9b2b20218538