Unit tests for SourceBuffer#abort().
Fixed to generate a failure result in case browser doesn't support a MIME used in the test.
Added more explanation what this code tests.
Added a unit test for SourceBuffer#abort() when the updating attribute is true.
Fixed WebM video to refer under /media directory.
Added test case for MP4 video. Fixed inconsistent spacing.
Fixed to replace video.canPlayType() with MediaSource.isTypeSupported().
Fixed to check the behavior when readySate attribute is not in the 'open' state.
Fixed not to use video elements and to create video element nodes by DOM API.
Fixed a function name 'test' not to conflict with testharness.js.
Merge pull request #849 from shishimaru/shishimaru/media-source-SourceBuffer-abort

Tests for SourceBuffer#abort()