Revert of Make WebKitCSSMatrix an alias of DOMMatrix (patchset #16 id:300001 of https://codereview.chromium.org/2709763004/ )

Reason for revert:
The WebKitCSSMatrix is not working after this change. Becuase the GeometryInterface is not shipped yet.

Original issue's description:
> Make WebkitCSSMatrix an alias of DOMMatrix
>
> DOMMatrix was changed sufficiently that WebKitCSSMatrix can be made a simple alias of it.
>
> Intent-to-ship Link :
> https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/
> cAiTOdSGyes/Su7dlx32EQAJ
>
> BUG=581955
>
> Review-Url: https://codereview.chromium.org/2709763004
> Cr-Commit-Position: refs/heads/master@{#479481}
> Committed: https://chromium.googlesource.com/chromium/src/+/0ac2b97eb15689ba196f7f88b184b3a17f13d30d

TBR=fserb@chromium.org,foolip@chromium.org,simonp@opera.com,timvolodine@chromium.org,dpranke@chromium.org,gogag2@gmail.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=581955

Review-Url: https://codereview.chromium.org/2943213002
Cr-Commit-Position: refs/heads/master@{#480276}
23 files changed