DevTools: Decouple shortcuts from actions, introduce shortcut contexts

R=eustas, pfeldman, vsevik
BUG=174309

Review URL: https://codereview.chromium.org/218613013

git-svn-id: svn://svn.chromium.org/blink/trunk@171867 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove unused RenderGeometryMap arg from RenderLayerRepainter::computeRepaintRect

BUG=

Review URL: https://codereview.chromium.org/240383002

git-svn-id: svn://svn.chromium.org/blink/trunk@171868 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Fix race condition in StyleSourceMapping's StyleFile binding.

R=pfeldman, lushnikov, apavlov
BUG=361578

Review URL: https://codereview.chromium.org/240053011

git-svn-id: svn://svn.chromium.org/blink/trunk@171869 bbb929c8-8fbe-4397-9dbb-9b2b20218538