Clean up testing.internals argument type checking.

Make use of [TypeChecking=Interface] where possible, fixing null pointer
deref over internals.addTextMatchMarker in the process.

R=haraken@chromium.org
BUG=375712

Review URL: https://codereview.chromium.org/445933003

git-svn-id: svn://svn.chromium.org/blink/trunk@179706 bbb929c8-8fbe-4397-9dbb-9b2b20218538
5 files changed
tree: d40517284f8196ab1a86ccba0948ae1e0e8eb0a0
  1. third_party/