The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bca17f295290d53553383c739ce5731e8158a643

commit bca17f295290d53553383c739ce5731e8158a643
Author: Fredrik Söderquist <fs@opera.com>
Date: Mon Oct 15 19:55:20 2018

Path2D.addPath should throw if DOMMatrix validation fails

Step two of [1], invokes [2], whose step 1 invokes [3], which says to
throw a TypeError if the dictionary is not "well-formed".

Also remove some dead code in DOMMatrix/DOMMatrixReadOnly and remove few
unused includes of svg_matrix_tear_off.h.

[1] https://html.spec.whatwg.org/multipage/canvas.html#dom-path2d-addpath
[2] https://drafts.fxtf.org/geometry/#create-a-dommatrix-from-the-2d-dictionary
[3] https://drafts.fxtf.org/geometry/#matrix-validate-and-fixup-2d

Bug:  895244 
Change-Id: Icd3f7058ce945d761ab7128e294ccc2e3fd3a879
Reviewed-on: https://chromium-review.googlesource.com/c/1278789
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#599723}
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/WebKit/LayoutTests/external/wpt/css/geometry/DOMMatrix2DInit-validate-fixup-expected.txt
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/core/geometry/dom_matrix.cc
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/core/geometry/dom_matrix.h
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/core/geometry/dom_matrix_read_only.cc
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/core/geometry/dom_matrix_read_only.h
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/modules/canvas/canvas2d/canvas_pattern.h
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/modules/canvas/canvas2d/path_2d.h
[modify] https://crrev.com/bca17f295290d53553383c739ce5731e8158a643/third_party/blink/renderer/modules/canvas/canvas2d/path_2d.idl