Remove TransformationMatrix::Create(...) in platform/transforms

As advised in [1], this CL removes unnecessary TransformationMatrix::Create(...)
in //third_party/blink/renderer/platform/transform and make it's
constructor public, then make the callers use std::make_unique<TransformationMatrix>
instead of it's Create() factory function.

[1] https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/iJ1bawbxbWs/vEdfT5QtBgAJ

Bug: 939691
Change-Id: I5be85eca16ff02c2c18faa1718829d1bc0ade855
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1530250
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Gyuyoung Kim <gyuyoung@igalia.com>
Cr-Commit-Position: refs/heads/master@{#641908}
19 files changed