Consistently use ExceptionState::throwTypeError().

Prefer this helper function when throwing TypeErrors.

R=
BUG=

Review URL: https://codereview.chromium.org/183253003

git-svn-id: svn://svn.chromium.org/blink/trunk@168247 bbb929c8-8fbe-4397-9dbb-9b2b20218538