WebKitCSSMatrix compat: constructors

Change fromString() static method into overloaded constructor,
since Web content depends on it for WebKitCSSMatrix constructor.
However, I could not find (github search) content that depends on
WebKitCSSMatrix(other), so leave as fromMatrix() static method.

Also add a no-argument constructor. I think this was accidentally
left out when switching to static methods.

Part of whatwg/compat#19

Author: zcorpan

geometry/Overview.bs

@@ -401,11 +401,12 @@ In the following sections, terms have the following meaning:
 </dl>
 
 <pre class='idl'>
-[Constructor(sequence&lt;unrestricted double> numberSequence),
+[Constructor,
+ Constructor(DOMString transformList),
+ Constructor(sequence&lt;unrestricted double> numberSequence),
  Exposed=(Window,Worker)]
 interface DOMMatrixReadOnly {
     [NewObject] static DOMMatrixReadOnly fromMatrix(optional DOMMatrixInit other);
-    [NewObject] static DOMMatrixReadOnly fromString(DOMString transformList);
     [NewObject] static DOMMatrixReadOnly fromFloat32Array(Float32Array array32);
     [NewObject] static DOMMatrixReadOnly fromFloat64Array(Float64Array array64);
 
@@ -474,11 +475,12 @@ interface DOMMatrixReadOnly {
                         serializer = { attribute };
 };
 
-[Constructor(sequence&lt;unrestricted double> numberSequence),
+[Constructor,
+ Constructor(DOMString transformList),
+ Constructor(sequence&lt;unrestricted double> numberSequence),
  Exposed=(Window,Worker)]
 interface DOMMatrix : DOMMatrixReadOnly {
     [NewObject] static DOMMatrix fromMatrix(optional DOMMatrixInit other);
-    [NewObject] static DOMMatrix fromString(DOMString transformList);
     [NewObject] static DOMMatrix fromFloat32Array(Float32Array array32);
     [NewObject] static DOMMatrix fromFloat64Array(Float64Array array64);
 
@@ -645,8 +647,43 @@ with a sequence <var>numberSequence</var> of 16 elements, follow these steps:
 1. Set <a>is2D</a> to <code>false</code>.
 1. Return <var>matrix</var>
 
+The <dfn dfn-type=constructor dfn-for=DOMMatrixReadOnly><code>DOMMatrixReadOnly()</code></dfn> and
+the <dfn dfn-type=constructor dfn-for=DOMMatrix><code>DOMMatrix()</code></dfn> constructors, when
+invoked with no argument, must run the following steps:
+
+<ol>
+  <li>Return the result of invoking <a>create a 2d matrix</a> of type {{DOMMatrixReadOnly}} or
+  {{DOMMatrix}} as appropriate, with the sequence [''1'', ''0'', ''0'', ''1'', ''0'', ''0''].</li>
+</ol>
+
+The <dfn dfn-type=constructor dfn-for=DOMMatrixReadOnly><code>DOMMatrixReadOnly(<var>transformList</var>)</code></dfn> and
+the <dfn dfn-type=constructor dfn-for=DOMMatrix><code>DOMMatrix(<var>transformList</var>)</code></dfn> constructors, when invoked with a {{DOMString}} argument, must follow these steps:
+
+<ol>
+  <li>Parse <var>transformList</var> by following the syntax description in “<a href=http://www.w3.org/TR/css-transforms-1/#svg-syntax>Syntax of the SVG ‘transform’ attribute</a>” [[!CSS3-TRANSFORMS]] to a <<transform-list>>. If parsing is not successful or any <<transform-function>> has <<length>> values without <a spec='css-values'>absolute length</a> units<!--For WD: <a spec='css-values-3'>absolute length units</a>-->, throw a {{SyntaxError}} exception.</li>
+  <li>Let <var>2dTransform</var> track the 2D/3D dimension status of the <<transform-list>>.
+    <dl class=switch>
+      <dt>If the <<transform-list>> consists of any <a href='http://www.w3.org/TR/css-transforms-1/#three-d-transform-functions'>3D Transform functions</a></dt>
+      <dd>Set <var>2dTransform</var> to <code>false</code>.</dd>
+      <dt>Otherwise</dt>
+      <dd>Set <var>2dTransform</var> to <code>true</code>.</dd>
+    </dl>
+  </li>
+  <li>Transform all <<transform-function>>s to 4x4 matrices by following the “<a href=http://www.w3.org/TR/css-transforms-1/#mathematical-description>Mathematical Description of Transform Functions</a>” [[!CSS3-TRANSFORMS]].</li>
+  <li>Let <var>matrix</var> be a 4x4 matrix as shown in the initial figure of this section. Post-multiply all matrices from left to right and set <var>matrix</var> to this product.</li>
+  <li>
+    <dl class=switch>
+      <dt>If <var>2dTransform</var> is set to <code>true</code></dt>
+      <dd>Return the result of invoking <a>create a 2d matrix</a> of type {{DOMMatrixReadOnly}} or {{DOMMatrix}} as appropriate, with a sequence of numbers, the values being the elements <var>m11</var>, <var>m12</var>, <var>m21</var>, <var>m22</var>, <var>m41</var> and <var>m42</var> of <var>matrix</var>.</dd>
+      <dt>If <var>2dTransform</var> is set to <code>false</code></dt>
+      <dd>Return the result of invoking <a>create a 3d matrix</a> of type {{DOMMatrixReadOnly}} or {{DOMMatrix}} as appropriate, with a sequence of numbers, the values being the 16 elements of <var>matrix</var>.</dd>
+    </dl>
+  </li>
+</ol>
+
 The <dfn dfn-type=constructor dfn-for=DOMMatrixReadOnly><code>DOMMatrixReadOnly(<var>numberSequence</var>)</code></dfn> and
-the <dfn dfn-type=constructor dfn-for=DOMMatrix><code>DOMMatrix(<var>numberSequence</var>)</code></dfn> constructors, when invoked, must run the following steps:
+the <dfn dfn-type=constructor dfn-for=DOMMatrix><code>DOMMatrix(<var>numberSequence</var>)</code></dfn> constructors,
+when invoked with a sequence argument, must run the following steps:
 
 <dl class=switch>
   <dt>If <var>numberSequence</var> has 6 elements</dt>
@@ -673,31 +710,6 @@ the <dfn method lt=fromMatrix() dfn-for=DOMMatrix id=dom-dommatrix-frommatrix><c
   </li>
 </ol>
 
-The <dfn method dfn-for=DOMMatrixReadOnly id=dom-dommatrixreadonly-fromstring><code>fromString(<var>transformList</var>)</code></dfn> static method on {{DOMMatrixReadOnly}} and
-the <dfn method dfn-for=DOMMatrix id=dom-dommatrix-fromstring><code>fromString(<var>transformList</var>)</code></dfn> static method on {{DOMMatrix}} must follow these steps:
-
-<ol>
-  <li>Parse <var>transformList</var> by following the syntax description in “<a href=http://www.w3.org/TR/css-transforms-1/#svg-syntax>Syntax of the SVG ‘transform’ attribute</a>” [[!CSS3-TRANSFORMS]] to a <<transform-list>>. If parsing is not successful or any <<transform-function>> has <<length>> values without <a spec='css-values'>absolute length</a> units<!--For WD: <a spec='css-values-3'>absolute length units</a>-->, throw a {{SyntaxError}} exception.</li>
-  <li>Let <var>2dTransform</var> track the 2D/3D dimension status of the <<transform-list>>.
-    <dl class=switch>
-      <dt>If the <<transform-list>> consists of any <a href='http://www.w3.org/TR/css-transforms-1/#three-d-transform-functions'>3D Transform functions</a></dt>
-      <dd>Set <var>2dTransform</var> to <code>false</code>.</dd>
-      <dt>Otherwise</dt>
-      <dd>Set <var>2dTransform</var> to <code>true</code>.</dd>
-    </dl>
-  </li>
-  <li>Transform all <<transform-function>>s to 4x4 matrices by following the “<a href=http://www.w3.org/TR/css-transforms-1/#mathematical-description>Mathematical Description of Transform Functions</a>” [[!CSS3-TRANSFORMS]].</li>
-  <li>Let <var>matrix</var> be a 4x4 matrix as shown in the initial figure of this section. Post-multiply all matrices from left to right and set <var>matrix</var> to this product.</li>
-  <li>
-    <dl class=switch>
-      <dt>If <var>2dTransform</var> is set to <code>true</code></dt>
-      <dd>Return the result of invoking <a>create a 2d matrix</a> of type {{DOMMatrixReadOnly}} or {{DOMMatrix}} as appropriate, with a sequence of numbers, the values being the elements <var>m11</var>, <var>m12</var>, <var>m21</var>, <var>m22</var>, <var>m41</var> and <var>m42</var> of <var>matrix</var> of <var>matrix</var>.</dd>
-      <dt>If <var>2dTransform</var> is set to <code>false</code></dt>
-      <dd>Return the result of invoking <a>create a 3d matrix</a> of type {{DOMMatrixReadOnly}} or {{DOMMatrix}} as appropriate, with a sequence of numbers, the values being the 16 elements of <var>matrix</var>.</dd>
-    </dl>
-  </li>
-</ol>
-
 The <dfn method dfn-for=DOMMatrixReadOnly id=dom-dommatrixreadonly-fromfloat32array><code>fromFloat32Array(<var>array32</var>)</code></dfn> static method on {{DOMMatrixReadOnly}} and
 the <dfn method dfn-for=DOMMatrix id=dom-dommatrix-fromfloat32array><code>fromFloat32Array(<var>array32</var>)</code></dfn> static method on {{DOMMatrix}} must follow these steps: