DevTools: disable CSS agent on disconnect.

BUG=358534
R=apavlov@chromium.org

Review URL: https://codereview.chromium.org/221033003

git-svn-id: svn://svn.chromium.org/blink/trunk@170577 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: fix leaking CSSRules through LiveLocations

This patch removes live location from header stylesheet on dispose
action.

Review URL: https://codereview.chromium.org/217423015

git-svn-id: svn://svn.chromium.org/blink/trunk@170578 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: wrap DebuggerAgent.Location with DebuggerModel.Location.

R=sergeyv@chromium.org

Review URL: https://codereview.chromium.org/220903002

git-svn-id: svn://svn.chromium.org/blink/trunk@170579 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Don't expose WebKitShadowRoot constructor.

It's time to expose only ShadowRoot constructor.
The chromium side patch is here: https://codereview.chromium.org/217013005/.

BUG=242153

Review URL: https://codereview.chromium.org/216123005

git-svn-id: svn://svn.chromium.org/blink/trunk@170580 bbb929c8-8fbe-4397-9dbb-9b2b20218538