DevTools: Change scale with Alt-mousewheel in Screencast view

BUG=286317

Review URL: https://chromiumcodereview.appspot.com/23707031

git-svn-id: svn://svn.chromium.org/blink/trunk@157597 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: update protocol version to 1.1

BUG=None

Review URL: https://chromiumcodereview.appspot.com/24105002

git-svn-id: svn://svn.chromium.org/blink/trunk@157598 bbb929c8-8fbe-4397-9dbb-9b2b20218538