Remove MicroData implementation

LayoutTests/platform/chromium/TestExpectations

 # These are the layout test expectations for the Chromium port(s) of WebKit.
 #
 # See http://trac.webkit.org/wiki/TestExpectations for more information on this file.
 
 # -----------------------------------------------------------------
 # SLOW TESTS
 # -----------------------------------------------------------------
 
 crbug.com/24182 [ Debug ] css3/flexbox/multiline-justify-content.html [ Slow ]
 webkit.org/b/91666 [ Mac ] editing/input/emacs-ctrl-o.html [ Failure Slow ]
@@ skipping 182 matching lines @@
 webkit.org/b/63933 fast/canvas/canvas-webkitLineDash-invalid.html [ Failure ]
 webkit.org/b/63933 virtual/gpu/fast/canvas/canvas-webkitLineDash.html [ Failure ]
 webkit.org/b/63933 virtual/gpu/fast/canvas/canvas-webkitLineDash-invalid.html [ Failure ]
 
 # Overflowing LayoutUnits cause RenderGeometryMap assertions
 webkit.org/b/67434 [ Debug ] fast/overflow/overflow-height-float-not-removed-crash.html [ Skip ]
 webkit.org/b/67434 [ Debug ] fast/overflow/overflow-height-float-not-removed-crash2.html [ Skip ]
 webkit.org/b/67434 [ Debug ] fast/overflow/overflow-height-float-not-removed-crash3.html [ Skip ]
 webkit.org/b/67434 [ Debug ] fast/block/float/overhanging-tall-block.html [ Skip ]
 
-# Microdata DOM API is not yet enabled.
-webkit.org/b/68610 fast/dom/MicroData
-
 # Unskip after changes on both sides have landed and rolled together.
 crbug.com/103939 http/tests/appcache/wrong-content-type.html [ Skip ]
 
 # Vibration API is not supported yet in the chromium port.
 webkit.org/b/72010 fast/dom/navigator-vibration.html
 
 # Battery Status API is not supported yet in the chromium port.
 webkit.org/b/62698 batterystatus
 
 # CSS image-resolution is not yet enabled.
@@ skipping 3547 matching lines @@
 crbug.com/230771 editing/pasteboard/drop-file-svg.html [ Failure ]
 crbug.com/230771 editing/pasteboard/file-drag-to-editable.html [ Failure ]
 crbug.com/230771 editing/pasteboard/file-input-files-access.html [ Failure ]
 crbug.com/230771 fast/events/drag-dataTransferItemList-file-handling.html [ Failure ]
 crbug.com/230771 fast/forms/file/file-input-change-event.html [ Failure ]
 crbug.com/230771 fast/forms/file/input-file-value.html [ Failure ]
 crbug.com/230771 fast/forms/file/input-file-write-files.html [ Failure ]
 crbug.com/230771 fast/forms/file/selected-files-from-history-state.html [ Failure ]
 crbug.com/230771 http/tests/security/clipboard/clipboard-file-access.html [ Failure ]
 crbug.com/230771 fast/forms/file/file-input-reset.html [ ImageOnlyFailure ]