diff --git a/components/script/dom/dommatrix.rs b/components/script/dom/dommatrix.rs
index bc57feb14fab..03e152a2f2c8 100644
--- a/components/script/dom/dommatrix.rs
+++ b/components/script/dom/dommatrix.rs
@@ -6,14 +6,17 @@ use crate::dom::bindings::codegen::Bindings::DOMMatrixBinding::{
     DOMMatrixInit, DOMMatrixMethods, Wrap,
 };
 use crate::dom::bindings::codegen::Bindings::DOMMatrixReadOnlyBinding::DOMMatrixReadOnlyMethods;
+use crate::dom::bindings::codegen::UnionTypes::StringOrUnrestrictedDoubleSequence;
+use crate::dom::bindings::error;
 use crate::dom::bindings::error::Fallible;
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::reflect_dom_object;
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::dommatrixreadonly::{
-    dommatrixinit_to_matrix, entries_to_matrix, DOMMatrixReadOnly,
+    dommatrixinit_to_matrix, entries_to_matrix, transform_to_matrix, DOMMatrixReadOnly,
 };
 use crate::dom::globalscope::GlobalScope;
+use crate::dom::window::Window;
 use dom_struct::dom_struct;
 use euclid::Transform3D;
 use js::rust::CustomAutoRooterGuard;
@@ -37,14 +40,32 @@ impl DOMMatrix {
         }
     }
 
-    // https://drafts.fxtf.org/geometry-1/#dom-dommatrix-dommatrix
-    pub fn Constructor(global: &GlobalScope) -> Fallible<DomRoot<Self>> {
-        Self::Constructor_(global, vec![1.0, 0.0, 0.0, 1.0, 0.0, 0.0])
-    }
-
-    // https://drafts.fxtf.org/geometry-1/#dom-dommatrix-dommatrix-numbersequence
-    pub fn Constructor_(global: &GlobalScope, entries: Vec<f64>) -> Fallible<DomRoot<Self>> {
-        entries_to_matrix(&entries[..]).map(|(is2D, matrix)| Self::new(global, is2D, matrix))
+    // https://drafts.fxtf.org/geometry-1/#dom-dommatrixreadonly-dommatrixreadonly
+    pub fn Constructor(
+        global: &GlobalScope,
+        init: Option<StringOrUnrestrictedDoubleSequence>,
+    ) -> Fallible<DomRoot<Self>> {
+        if init.is_none() {
+            return Ok(Self::new(global, true, Transform3D::identity()));
+        }
+        match init.unwrap() {
+            StringOrUnrestrictedDoubleSequence::String(ref s) => {
+                if global.downcast::<Window>().is_none() {
+                    return Err(error::Error::Type(
+                        "String constructor is only supported in the main thread.".to_owned(),
+                    ));
+                }
+                if s.is_empty() {
+                    return Ok(Self::new(global, true, Transform3D::identity()));
+                }
+                transform_to_matrix(s.to_string())
+                    .map(|(is2D, matrix)| Self::new(global, is2D, matrix))
+            },
+            StringOrUnrestrictedDoubleSequence::UnrestrictedDoubleSequence(ref entries) => {
+                entries_to_matrix(&entries[..])
+                    .map(|(is2D, matrix)| Self::new(global, is2D, matrix))
+            },
+        }
     }
 
     // https://drafts.fxtf.org/geometry-1/#dom-dommatrix-frommatrix
@@ -62,7 +83,10 @@ impl DOMMatrix {
         array: CustomAutoRooterGuard<Float32Array>,
     ) -> Fallible<DomRoot<DOMMatrix>> {
         let vec: Vec<f64> = array.to_vec().iter().map(|&x| x as f64).collect();
-        DOMMatrix::Constructor_(global, vec)
+        DOMMatrix::Constructor(
+            global,
+            Some(StringOrUnrestrictedDoubleSequence::UnrestrictedDoubleSequence(vec)),
+        )
     }
 
     // https://drafts.fxtf.org/geometry-1/#dom-dommatrix-fromfloat64array
@@ -71,7 +95,10 @@ impl DOMMatrix {
         array: CustomAutoRooterGuard<Float64Array>,
     ) -> Fallible<DomRoot<DOMMatrix>> {
         let vec: Vec<f64> = array.to_vec();
-        DOMMatrix::Constructor_(global, vec)
+        DOMMatrix::Constructor(
+            global,
+            Some(StringOrUnrestrictedDoubleSequence::UnrestrictedDoubleSequence(vec)),
+        )
     }
 }
 
diff --git a/components/script/dom/dommatrixreadonly.rs b/components/script/dom/dommatrixreadonly.rs
index 010f823e78c7..fae6afe1649f 100644
--- a/components/script/dom/dommatrixreadonly.rs
+++ b/components/script/dom/dommatrixreadonly.rs
@@ -8,13 +8,17 @@ use crate::dom::bindings::codegen::Bindings::DOMMatrixReadOnlyBinding::{
     DOMMatrixReadOnlyMethods, Wrap,
 };
 use crate::dom::bindings::codegen::Bindings::DOMPointBinding::DOMPointInit;
+use crate::dom::bindings::codegen::UnionTypes::StringOrUnrestrictedDoubleSequence;
 use crate::dom::bindings::error;
 use crate::dom::bindings::error::Fallible;
+use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::dommatrix::DOMMatrix;
 use crate::dom::dompoint::DOMPoint;
 use crate::dom::globalscope::GlobalScope;
+use crate::dom::window::Window;
+use cssparser::{Parser, ParserInput};
 use dom_struct::dom_struct;
 use euclid::{Angle, Transform3D};
 use js::jsapi::{JSContext, JSObject};
@@ -25,6 +29,7 @@ use std::cell::{Cell, Ref};
 use std::f64;
 use std::ptr;
 use std::ptr::NonNull;
+use style::parser::ParserContext;
 
 #[dom_struct]
 pub struct DOMMatrixReadOnly {
@@ -49,13 +54,31 @@ impl DOMMatrixReadOnly {
     }
 
     // https://drafts.fxtf.org/geometry-1/#dom-dommatrixreadonly-dommatrixreadonly
-    pub fn Constructor(global: &GlobalScope) -> Fallible<DomRoot<Self>> {
-        Ok(Self::new(global, true, Transform3D::identity()))
-    }
-
-    // https://drafts.fxtf.org/geometry-1/#dom-dommatrixreadonly-dommatrixreadonly-numbersequence
-    pub fn Constructor_(global: &GlobalScope, entries: Vec<f64>) -> Fallible<DomRoot<Self>> {
-        entries_to_matrix(&entries[..]).map(|(is2D, matrix)| Self::new(global, is2D, matrix))
+    pub fn Constructor(
+        global: &GlobalScope,
+        init: Option<StringOrUnrestrictedDoubleSequence>,
+    ) -> Fallible<DomRoot<Self>> {
+        if init.is_none() {
+            return Ok(Self::new(global, true, Transform3D::identity()));
+        }
+        match init.unwrap() {
+            StringOrUnrestrictedDoubleSequence::String(ref s) => {
+                if global.downcast::<Window>().is_none() {
+                    return Err(error::Error::Type(
+                        "String constructor is only supported in the main thread.".to_owned(),
+                    ));
+                }
+                if s.is_empty() {
+                    return Ok(Self::new(global, true, Transform3D::identity()));
+                }
+                transform_to_matrix(s.to_string())
+                    .map(|(is2D, matrix)| Self::new(global, is2D, matrix))
+            },
+            StringOrUnrestrictedDoubleSequence::UnrestrictedDoubleSequence(ref entries) => {
+                entries_to_matrix(&entries[..])
+                    .map(|(is2D, matrix)| Self::new(global, is2D, matrix))
+            },
+        }
     }
 
     // https://drafts.fxtf.org/geometry-1/#dom-dommatrixreadonly-frommatrix
@@ -372,7 +395,10 @@ impl DOMMatrixReadOnly {
         array: CustomAutoRooterGuard<Float32Array>,
     ) -> Fallible<DomRoot<DOMMatrixReadOnly>> {
         let vec: Vec<f64> = array.to_vec().iter().map(|&x| x as f64).collect();
-        DOMMatrixReadOnly::Constructor_(global, vec)
+        DOMMatrixReadOnly::Constructor(
+            global,
+            Some(StringOrUnrestrictedDoubleSequence::UnrestrictedDoubleSequence(vec)),
+        )
     }
 
     // https://drafts.fxtf.org/geometry-1/#dom-dommatrixreadonly-fromfloat64array
@@ -382,7 +408,10 @@ impl DOMMatrixReadOnly {
         array: CustomAutoRooterGuard<Float64Array>,
     ) -> Fallible<DomRoot<DOMMatrixReadOnly>> {
         let vec: Vec<f64> = array.to_vec();
-        DOMMatrixReadOnly::Constructor_(global, vec)
+        DOMMatrixReadOnly::Constructor(
+            global,
+            Some(StringOrUnrestrictedDoubleSequence::UnrestrictedDoubleSequence(vec)),
+        )
     }
 }
 
@@ -759,3 +788,32 @@ fn normalize_point(x: f64, y: f64, z: f64) -> (f64, f64, f64) {
         (x / len, y / len, z / len)
     }
 }
+
+pub fn transform_to_matrix(value: String) -> Fallible<(bool, Transform3D<f64>)> {
+    use style::properties::longhands::transform;
+
+    let mut input = ParserInput::new(&value);
+    let mut parser = Parser::new(&mut input);
+    let url = ::servo_url::ServoUrl::parse("about:blank").unwrap();
+    let context = ParserContext::new(
+        ::style::stylesheets::Origin::Author,
+        &url,
+        Some(::style::stylesheets::CssRuleType::Style),
+        ::style_traits::ParsingMode::DEFAULT,
+        ::style::context::QuirksMode::NoQuirks,
+        None,
+        None,
+    );
+
+    let transform = match parser.parse_entirely(|t| transform::parse(&context, t)) {
+        Ok(result) => result,
+        Err(..) => return Err(error::Error::Syntax),
+    };
+
+    let (m, is_3d) = match transform.to_transform_3d_matrix_f64(None) {
+        Ok(result) => result,
+        Err(..) => return Err(error::Error::Syntax),
+    };
+
+    Ok((!is_3d, m))
+}
diff --git a/components/script/dom/webidls/DOMMatrix.webidl b/components/script/dom/webidls/DOMMatrix.webidl
index 6facefec0569..d617f20af99c 100644
--- a/components/script/dom/webidls/DOMMatrix.webidl
+++ b/components/script/dom/webidls/DOMMatrix.webidl
@@ -10,9 +10,7 @@
  * related or neighboring rights to this work.
  */
 
-[Constructor,
- // Constructor(DOMString transformList),
- Constructor(sequence<unrestricted double> numberSequence),
+[Constructor(optional (DOMString or sequence<unrestricted double>) init),
  Exposed=(Window,Worker)]
 interface DOMMatrix : DOMMatrixReadOnly {
 
diff --git a/components/script/dom/webidls/DOMMatrixReadOnly.webidl b/components/script/dom/webidls/DOMMatrixReadOnly.webidl
index 2382275e2494..dcd9229b3d74 100644
--- a/components/script/dom/webidls/DOMMatrixReadOnly.webidl
+++ b/components/script/dom/webidls/DOMMatrixReadOnly.webidl
@@ -10,9 +10,7 @@
  * related or neighboring rights to this work.
  */
 
-[Constructor,
- // Constructor(DOMString transformList)
- Constructor(sequence<unrestricted double> numberSequence),
+[Constructor(optional (DOMString or sequence<unrestricted double>) init),
  Exposed=(Window,Worker)]
 interface DOMMatrixReadOnly {
 
diff --git a/components/style/values/generics/transform.rs b/components/style/values/generics/transform.rs
index ba0e320865a6..64fb1e254a5d 100644
--- a/components/style/values/generics/transform.rs
+++ b/components/style/values/generics/transform.rs
@@ -542,6 +542,19 @@ impl<T: ToMatrix> Transform<T> {
             )
         };
 
+        let (m, is_3d) = match self.to_transform_3d_matrix_f64(reference_box) {
+            Ok(result) => result,
+            Err(err) => return Err(err),
+        };
+
+        Ok((cast_3d_transform(m), is_3d))
+    }
+
+    /// Same as Transform::to_transform_3d_matrix but a f64 version.
+    pub fn to_transform_3d_matrix_f64(
+        &self,
+        reference_box: Option<&Rect<Au>>,
+    ) -> Result<(Transform3D<f64>, bool), ()> {
         // We intentionally use Transform3D<f64> during computation to avoid error propagation
         // because using f32 to compute triangle functions (e.g. in create_rotation()) is not
         // accurate enough. In Gecko, we also use "double" to compute the triangle functions.
@@ -556,7 +569,7 @@ impl<T: ToMatrix> Transform<T> {
             transform = transform.pre_mul(&matrix);
         }
 
-        Ok((cast_3d_transform(transform), contain_3d))
+        Ok((transform, contain_3d))
     }
 }
 
diff --git a/tests/wpt/metadata/css/geometry/DOMMatrix-001.html.ini b/tests/wpt/metadata/css/geometry/DOMMatrix-001.html.ini
index f6cc19731440..c2c132ec2622 100644
--- a/tests/wpt/metadata/css/geometry/DOMMatrix-001.html.ini
+++ b/tests/wpt/metadata/css/geometry/DOMMatrix-001.html.ini
@@ -1,293 +1,19 @@
 [DOMMatrix-001.html]
   type: testharness
-  [testConstructor1]
-    expected: FAIL
-
-  [testConstructor2]
-    expected: FAIL
-
-  [testConstructor3]
-    expected: FAIL
-
-  [testConstructor5]
-    expected: FAIL
-
-  [testConstructor7]
-    expected: FAIL
-
-  [testConstructor8]
-    expected: FAIL
-
-  [testConstructor9]
-    expected: FAIL
-
-  [testConstructor10]
-    expected: FAIL
-
-  [testConstructor11]
-    expected: FAIL
-
-  [testConstructor13]
-    expected: FAIL
-
-  [testConstructorIllegal0]
-    expected: FAIL
-
-  [new DOMMatrix(undefined)]
-    expected: FAIL
-
   [new DOMMatrix(new DOMMatrix())]
     expected: FAIL
 
-  [new DOMMatrix("none")]
-    expected: FAIL
-
-  [new DOMMatrix(" none")]
-    expected: FAIL
-
-  [new DOMMatrix("none ")]
-    expected: FAIL
-
-  [new DOMMatrix("NONE")]
-    expected: FAIL
-
-  [new DOMMatrix("none/**/")]
-    expected: FAIL
-
-  [new DOMMatrix("/**/none")]
-    expected: FAIL
-
-  [new DOMMatrix("")]
-    expected: FAIL
-
-  [new DOMMatrix("scale(2) translateX(5px) translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrix("scale(2, 2) translateX(5px) translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrix("scale(2)translateX(5px)translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrix("scale(2) translateX(calc(2 * 2.5px)) translateY(5px)")]
-    expected: FAIL
-
   [new DOMMatrix("scale(2) translateX(5px) translateY(5px) rotate(5deg) rotate(-5deg)")]
     expected: FAIL
 
-  [new DOMMatrix("translateX    (5px)")]
-    expected: FAIL
-
-  [new DOMMatrix("scale(2 2) translateX(5) translateY(5)")]
-    expected: FAIL
-
-  [new DOMMatrix("scale(2, 2), translateX(5)  ,translateY(5)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5em)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5ex)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5ch)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5rem)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5vw)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5vh)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5vmin)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5vmax)")]
-    expected: FAIL
-
-  [new DOMMatrix("translateX(5%)")]
-    expected: FAIL
-
-  [new DOMMatrix("rotate(5)")]
-    expected: FAIL
-
-  [new DOMMatrix("rotate(5, 5, 5)")]
-    expected: FAIL
-
-  [new DOMMatrix("rotate(5, 5px, 5px)")]
-    expected: FAIL
-
-  [new DOMMatrix("rotate(5deg, 5px, 5px)")]
-    expected: FAIL
-
-  [new DOMMatrix(" ")]
-    expected: FAIL
-
-  [new DOMMatrix("/**/")]
-    expected: FAIL
-
-  [new DOMMatrix("\\0")]
-    expected: FAIL
-
-  [new DOMMatrix(";")]
-    expected: FAIL
-
-  [new DOMMatrix("none;")]
-    expected: FAIL
-
-  [new DOMMatrix("null")]
-    expected: FAIL
-
-  [new DOMMatrix(null)]
-    expected: FAIL
-
-  [new DOMMatrix("undefined")]
-    expected: FAIL
-
-  [new DOMMatrix("inherit")]
-    expected: FAIL
-
-  [new DOMMatrix("initial")]
-    expected: FAIL
-
-  [new DOMMatrix("unset")]
-    expected: FAIL
-
   [new DOMMatrix(matrix)]
     expected: FAIL
 
-  [new DOMMatrix("scale(2, 2), translateX(5px) translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly(undefined)]
-    expected: FAIL
-
   [new DOMMatrixReadOnly(new DOMMatrixReadOnly())]
     expected: FAIL
 
-  [new DOMMatrixReadOnly("none")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly(" none")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("none ")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("NONE")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("none/**/")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("/**/none")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2) translateX(5px) translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2, 2) translateX(5px) translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2)translateX(5px)translateY(5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2) translateX(calc(2 * 2.5px)) translateY(5px)")]
-    expected: FAIL
-
   [new DOMMatrixReadOnly("scale(2) translateX(5px) translateY(5px) rotate(5deg) rotate(-5deg)")]
     expected: FAIL
 
-  [new DOMMatrixReadOnly("translateX    (5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2 2) translateX(5) translateY(5)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2, 2), translateX(5)  ,translateY(5)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5em)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5ex)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5ch)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5rem)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5vw)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5vh)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5vmin)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5vmax)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("translateX(5%)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("rotate(5)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("rotate(5, 5, 5)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("rotate(5, 5px, 5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("rotate(5deg, 5px, 5px)")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly(" ")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("/**/")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("\\0")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly(";")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("none;")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("null")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly(null)]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("undefined")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("inherit")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("initial")]
-    expected: FAIL
-
-  [new DOMMatrixReadOnly("unset")]
-    expected: FAIL
-
   [new DOMMatrixReadOnly(matrix)]
     expected: FAIL
-
-  [new DOMMatrixReadOnly("scale(2, 2), translateX(5px) translateY(5px)")]
-    expected: FAIL
-