Remove radiusY and rotation arguments from arcTo() method

They are not implemented and nobody is interested.

Partially reverts e25d3f9.

Fixes whatwg#878.

source

@@ -59838,7 +59838,6 @@ interface mixin <dfn>CanvasPath</dfn> {
   void <span data-x="dom-context-2d-quadraticCurveTo">quadraticCurveTo</span>(unrestricted double cpx, unrestricted double cpy, unrestricted double x, unrestricted double y);
   void <span data-x="dom-context-2d-bezierCurveTo">bezierCurveTo</span>(unrestricted double cp1x, unrestricted double cp1y, unrestricted double cp2x, unrestricted double cp2y, unrestricted double x, unrestricted double y);
   void <span data-x="dom-context-2d-arcTo">arcTo</span>(unrestricted double x1, unrestricted double y1, unrestricted double x2, unrestricted double y2, unrestricted double radius); <!-- see ARC-ORDER note below -->
-  void <span data-x="dom-context-2d-arcTo">arcTo</span>(unrestricted double x1, unrestricted double y1, unrestricted double x2, unrestricted double y2, unrestricted double radiusX, unrestricted double radiusY, unrestricted double rotation); <!-- see ARC-ORDER note below -->
   void <span data-x="dom-context-2d-rect">rect</span>(unrestricted double x, unrestricted double y, unrestricted double w, unrestricted double h);
   void <span data-x="dom-context-2d-arc">arc</span>(unrestricted double x, unrestricted double y, unrestricted double radius, unrestricted double startAngle, unrestricted double endAngle, optional boolean anticlockwise = false); <!-- see ARC-ORDER note below -->
   void <span data-x="dom-context-2d-ellipse">ellipse</span>(unrestricted double x, unrestricted double y, unrestricted double radiusX, unrestricted double radiusY, unrestricted double rotation, unrestricted double startAngle, unrestricted double endAngle, optional boolean anticlockwise = false); <!-- see ARC-ORDER note below -->
@@ -61192,19 +61191,14 @@ transform. ack Shaun Morris. -->
 
    </dd>
 
-   <dt><var>context</var> . <code subdfn data-x="dom-context-2d-arcTo">arcTo</code>(<var>x1</var>, <var>y1</var>, <var>x2</var>, <var>y2</var>, <var>radiusX</var> [, <var>radiusY</var>, <var>rotation</var> ] )</dt>
-   <dt><var>path</var> . <code data-x="dom-context-2d-arcTo">arcTo</code>(<var>x1</var>, <var>y1</var>, <var>x2</var>, <var>y2</var>, <var>radiusX</var> [, <var>radiusY</var>, <var>rotation</var> ] )</dt>
+   <dt><var>context</var> . <code subdfn data-x="dom-context-2d-arcTo">arcTo</code>(<var>x1</var>, <var>y1</var>, <var>x2</var>, <var>y2</var>, <var>radius</var>)</dt>
+   <dt><var>path</var> . <code data-x="dom-context-2d-arcTo">arcTo</code>(<var>x1</var>, <var>y1</var>, <var>x2</var>, <var>y2</var>, <var>radius</var>)</dt>
 
    <dd>
 
     <p>Adds an arc with the given control points and radius to the current subpath, connected to the
     previous point by a straight line.</p>
 
-    <p>If two radii are provided, then the first controls the width of the arc's ellipse, and the
-    second controls the height. If only one is provided, or if they are the same, then the arc is
-    from a circle. In the case of an ellipse, the rotation argument controls the clockwise
-    inclination of the ellipse relative to the x-axis.</p>
-
     <p>Throws an <span>"<code>IndexSizeError</code>"</span> <code>DOMException</code> if the given
     radius is negative.</p>
 
@@ -61647,20 +61641,16 @@ try {
   <hr>
 
   <p>The <dfn><code data-x="dom-context-2d-arcTo">arcTo(<var>x1</var>, <var>y1</var>, <var>x2</var>,
-  <var>y2</var>, <var>radiusX</var>, <var>radiusY</var>, <var>rotation</var>)</code></dfn> method,
-  when invoked, must run these steps:</p>
+  <var>y2</var>, <var>radius</var>)</code></dfn> method, when invoked, must run these steps:</p>
 
   <ol>
    <li><p>If any of the arguments are infinite or NaN, then return.</p></li>
 
    <li><p><span>Ensure there is a subpath</span> for <span data-x="">(<var>x1</var>,
    <var>y1</var>)</span>.</p></li>
 
-   <li><p>If either <var>radiusX</var> or <var>radiusY</var> are negative, then throw an
-   <span>"<code>IndexSizeError</code>"</span> <code>DOMException</code>.</p></li>
-
-   <li><p>If <var>radiusY</var> is omitted, then set <var>radiusY</var> to
-   <var>radiusX</var>.</p></li>
+   <li><p>If <var>radius</var> is negative, then throw an <span>"<code>IndexSizeError</code>"</span>
+   <code>DOMException</code>.</p></li>
 
    <li><p>Let the point (<var>x0</var>, <var>y0</var>) be the last point in the subpath, transformed
    by the inverse of the <span data-x="dom-context-2d-transformation">current transformation
@@ -61669,26 +61659,25 @@ try {
 
    <li><p>If the point (<var>x0</var>, <var>y0</var>) is equal to the point (<var>x1</var>,
    <var>y1</var>), or if the point (<var>x1</var>, <var>y1</var>) is equal to the point
-   (<var>x2</var>, <var>y2</var>), or if both <var>radiusX</var> and <var>radiusY</var> are zero,
-   then add the point (<var>x1</var>, <var>y1</var>) to the subpath, and connect that point to the
-   previous point (<var>x0</var>, <var>y0</var>) by a straight line.</p></li>
+   (<var>x2</var>, <var>y2</var>), or if <var>radius</var> is zero, then add the point
+   (<var>x1</var>, <var>y1</var>) to the subpath, and connect that point to the previous point
+   (<var>x0</var>, <var>y0</var>) by a straight line.</p></li>
 
    <li><p>Otherwise, if the points (<var>x0</var>, <var>y0</var>), (<var>x1</var>, <var>y1</var>),
    and (<var>x2</var>, <var>y2</var>) all lie on a single straight line, then add the point
    (<var>x1</var>, <var>y1</var>) to the subpath, and connect that point to the previous point
    (<var>x0</var>, <var>y0</var>) by a straight line.</p></li>
 
-   <li><p>Otherwise, let <var>The Arc</var> be the shortest arc given by circumference of the
-   ellipse that has radius <var>radiusX</var> on the major axis and radius <var>radiusY</var> on the
-   minor axis, and whose semi-major axis is rotated <var>rotation</var> radians clockwise from the
-   positive x-axis, and that has one point tangent to the half-infinite line that crosses the point
-   (<var>x0</var>, <var>y0</var>) and ends at the point (<var>x1</var>, <var>y1</var>), and that has
-   a different point tangent to the half-infinite line that ends at the point (<var>x1</var>,
-   <var>y1</var>) and crosses the point (<var>x2</var>, <var>y2</var>). The points at which this
-   ellipse touches these two lines are called the start and end tangent points respectively. Connect
-   the point (<var>x0</var>, <var>y0</var>) to the start tangent point by a straight line, adding
-   the start tangent point to the subpath, and then connect the start tangent point to the end
-   tangent point by <var>The Arc</var>, adding the end tangent point to the subpath.</p></li>
+   <li><p>Otherwise, let <var>The Arc</var> be the shortest arc given by circumference of the circle
+   that has radius <var>radius</var>, and that has one point tangent to the half-infinite line that
+   crosses the point (<var>x0</var>, <var>y0</var>) and ends at the point (<var>x1</var>,
+   <var>y1</var>), and that has a different point tangent to the half-infinite line that ends at the
+   point (<var>x1</var>, <var>y1</var>) and crosses the point (<var>x2</var>, <var>y2</var>). The
+   points at which this circle touches these two lines are called the start and end tangent points
+   respectively. Connect the point (<var>x0</var>, <var>y0</var>) to the start tangent point by a
+   straight line, adding the start tangent point to the subpath, and then connect the start tangent
+   point to the end tangent point by <var>The Arc</var>, adding the end tangent point to the
+   subpath.</p></li>
   </ol>
 
   <hr>