Suppress coverage information for mac python system libs

This cleans up the output from test-webkitpy -c on the mac a bit.

R=eseidel@chromium.org, ojan@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19721003

git-svn-id: svn://svn.chromium.org/blink/trunk@154474 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Use jsdocs @template for custom Array methods and remove corresponding casts.

BUG=None
R=vsevik@chromium.org

Review URL: https://codereview.chromium.org/19598003

git-svn-id: svn://svn.chromium.org/blink/trunk@154475 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rename focusedNode to focusedElement in Document.

This is a preparation to remove focus-related features from Node class.
This was inspired by akling's WebKit changes.

BUG=258763

Review URL: https://chromiumcodereview.appspot.com/19669013

git-svn-id: svn://svn.chromium.org/blink/trunk@154476 bbb929c8-8fbe-4397-9dbb-9b2b20218538