Add inspector ids of layer owner nodes to GraphicsLayerDebugInfo

... so that we can match layers to DOM nodes in DevTools layer tree
view.

BUG=361045

Review URL: https://codereview.chromium.org/279553002

git-svn-id: svn://svn.chromium.org/blink/trunk@173858 bbb929c8-8fbe-4397-9dbb-9b2b20218538