Import MSE tests from web-platform-tests

third_party/WebKit/LayoutTests/W3CImportExpectations

 # This file controls which subdirectories of the w3c test repos we import.
 #
 # This file acts as a blacklist; directories and files not listed here will
 # automatically be found and imported.
 #
 # This file is read by webkitpy/w3c/directory_owners_extractor.py to decide who
 # to contact for new failures; it will read entries with the following format:
 # When removing blacklist entries:
 # * Comment out the line rather than deleting it, to show it is intentional.
 # * Change [ Skip ] to [ Pass ]
@@ skipping 271 matching lines @@
 external/wpt/js [ Skip ]
 external/wpt/lint [ Skip ]
 external/wpt/manifest [ Skip ]
 external/wpt/mathml [ Skip ]
 ## Owners: none; No tests in the directory.
 # external/wpt/media [ Pass ]
 ## Owners: mlamouri@chromium.org,zqzhang@chromium.org
 # external/wpt/mediasession [ Pass ]
 ## Owners: chcunningham@chromium.org,mlamouri@chromium.org
 # external/wpt/media-capabilities
-external/wpt/media-source [ Skip ]
+## Owners: chcunningham@chromium.org,wolenetz@chromium.org
+# external/wpt/media-source [ Pass ]
 ## Owners: mcasas@chromium.org
 # external/wpt/mediacapture-record [ Pass ]
 ## Owners: phoglund@chromium.org
 # external/wpt/mediacapture-streams [ Pass ]
 external/wpt/microdata [ Skip ]
 ## Owners: mkwst@chromium.org
 # external/wpt/mixed-content [ Pass ]
 ## Owners: sunjian@chromium.org,panicker@chromium.org
 external/wpt/navigation-timing [ Pass ]
 ## Owners: platform-capabilities@chromium.org
@@ skipping 416 matching lines @@
 external/wpt/uievents/order-of-events/focus-events/focus-contained-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/focus-events/legacy-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/click-cancel-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/click-on-body-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/click-on-div-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/click-on-html-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/click-order-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/mouseevents-mousemove-manual.htm [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/mousemove-across-manual.html [ Skip ]
 external/wpt/uievents/order-of-events/mouse-events/mousemove-between-manual.html [ Skip ]