[linking] Deprecating viewTarget attribute on the <view> element

RESOLUTION: We will remove the <view viewTarget> attribute, its DOM
property, and the corresponding view spec argument.

A bit of context here - on the meeting we've discussed that the
attribute was create in hope to allow some sort of automatic
positioning, sizing and clipping of the views based on viewTarget
elements. However we've confirmed that no browser engine (Blink, Gecko,
Edge) implements it this way and viewTarget has no functional effect on
the presentation of SVG content. We've also confirmed there are no open
issues on Blink, Gecko, Edge and no indication of author interest
(Stackoverflow, GitHub). Even with good intentions the attribute wasn't
spec'd enough in SVG 1.1 or SVG 2 and we've agreed to remove the
attribute (+ DOM, svgView specification).

master/definitions.xml

@@ -527,7 +527,6 @@
       attributecategories='aria, core, global event'
       attributes='viewBox, preserveAspectRatio, zoomAndPan'
       interfaces='SVGViewElement'>
-    <attribute name='viewTarget' elements='view' href='linking.html#ViewElementViewTargetAttribute'/>
   </element>
 
   <!-- ... element categories ............................................ -->

master/linking.html

@@ -564,13 +564,11 @@ <h3 id="SVGFragmentIdentifiersDefinitions">SVG fragment identifiers definitions<
 SVGViewAttribute ::= viewBoxSpec |
                      preserveAspectRatioSpec |
                      transformSpec |
-                     zoomAndPanSpec |
-                     viewTargetSpec
+                     zoomAndPanSpec
 viewBoxSpec ::= 'viewBox(' ViewBoxParams ')'
 preserveAspectRatioSpec = 'preserveAspectRatio(' AspectParams ')'
 transformSpec ::= 'transform(' TransformParams ')'
 zoomAndPanSpec ::= 'zoomAndPan(' ZoomAndPanParams ')'
-viewTargetSpec ::= 'viewTarget(' ViewTargetParams ')'
 </pre>
 
 <p>where:</p>
@@ -596,9 +594,6 @@ <h3 id="SVGFragmentIdentifiersDefinitions">SVG fragment identifiers definitions<
   parameter values for the <a>'zoomAndPan'</a> attribute on the <a>'view'</a>
   element. For example, <span class="attr-value">zoomAndPan(magnify)</span>.</li>
 
-  <li><span class="code-fragment">ViewTargetParams</span> corresponds to the
-  parameter values for the <a>'view/viewTarget'</a> attribute on the <a>'view'</a>
-  element. For example, <span class="attr-value">viewTarget(MyElementID)</span>.</li>
 </ul>
 
 <p>SVG view box parameters are applied in order, as defined in
@@ -691,56 +686,8 @@ <h3 id="ViewElement">Predefined views: the <span class="element-name">'view'</sp
 <p>The <span class="element-name">'view'</span> element is defined as follows:</p>
 
 <edit:elementsummary name='view'/>
-
-<p><em>Attribute definitions:</em></p>
-
-<dl class="attrdef-list">
-  <dt>
-    <table class="propdef attrdef">
-      <tr>
-        <th>Name</th>
-        <th>Value</th>
-        <th>Initial value</th>
-        <th>Animatable</th>
-      </tr>
-      <tr>
-        <td><dfn id="ViewElementViewTargetAttribute">viewTarget</dfn></td>
-        <td>(see below)</td>
-        <td>(none)</td>
-        <td>no</td>
-      </tr>
-    </table>
-  </dt>
-  <dd>
-    Indicates the target object associated with the view.  This attribute
-    must be any value other than the empty string.
-      <div class="issue" data-issue="12">
-          Define the expected effect of declaring a 'viewTarget', here or in
-          an svgView target fragment.
-      </div>
-  </dd>
-</dl>
-
 </edit:with>
 
-<h3 id="ViewHighlight">Highlighting views</h3>
-
-    <div class="issue" data-issue="13">
-      This section and example needs to be updated subject to a decision on
-      whether 'viewTarget' should cause a match to the ':target' pseudoclass.
-    </div>
-
-<p>It is helpful to users if the target element(s) are highlighted. The visual
-styling of this highlight should be decided by the document author, because the
-<a>SVG user agent</a> has no way to determine what changes would make the
-elements more visible.</p>
-
-<p>The CSS :target selector ([<a href="refs.html#ref-SELECTORS">SELECTORS</a>],
-section 6.2.2) may be used in a stylesheet to provide alternate styling for
-elements which are the target of links. For example:</p>
-
-<edit:example href="images/linking/target.xml" image="no" link="no"/>
-
 <h2 id="DOMInterfaces">DOM interfaces</h2>
 
 <div class='ready-for-wg-review'>
@@ -768,16 +715,11 @@ <h3 id="InterfaceSVGViewElement">Interface SVGViewElement</h3>
 
 <p>An <a>SVGViewElement</a> object represents a <a>'view'</a> element in the DOM.</p>
 
-<pre class="idl">interface <b>SVGViewElement</b> : <a>SVGElement</a> {
-  [SameObject] readonly attribute <a>SVGStringList</a> <a href="linking.html#__svg__SVGViewElement__viewTarget">viewTarget</a>;
-};
+<pre class="idl">interface <b>SVGViewElement</b> : <a>SVGElement</a>;
 
 <a>SVGViewElement</a> implements <a>SVGFitToViewBox</a>;
 <a>SVGViewElement</a> implements <a>SVGZoomAndPan</a>;</pre>
 
-<p>The <b id="__svg__SVGViewElement__viewTarget">viewTarget</b> IDL attribute
-<a>reflects</a> the <a>'viewTarget'</a> content attribute.</p>
-
 </edit:with>
 </div>