Improve media-related exception messages

The two in HTMLMediaElement were just wrong.

Add a video-currentTime-set-with-controller.html test as that code path
was apparently untested before.

BUG=270033

Review URL: https://codereview.chromium.org/197213012

git-svn-id: svn://svn.chromium.org/blink/trunk@169314 bbb929c8-8fbe-4397-9dbb-9b2b20218538
14 files changed
tree: ce3e3f39002fa6af538afeb8404d0cad15663541
  1. third_party/