[css3-conditional] Describe requirements for conditionText getter on CSSSupportsRule.

This implements the resolution in
http://lists.w3.org/Archives/Public/www-style/2012Aug/0749.html
to address the second point in
http://lists.w3.org/Archives/Public/www-style/2013Feb/0228.html
which is Issue 8 in the Last Call Disposition of Comments.

It also adds a parenthetical to clarify the issue rejected in
http://lists.w3.org/Archives/Public/www-style/2012Dec/0102.html

Author: dbaron

css3-conditional/Overview.html

@@ -1214,6 +1214,7 @@ <h3 id=the-cssmediarule-interface><span class=secno>7.4. </span> The <a
     with the ‘<code class=css>@media</code>’ rule.
 
    <dt><code>conditionText</code> of type <code>DOMString</code>
+    (CSSMediaRule-specific definition for attribute on CSSConditionRule)
 
    <dd>The <code>conditionText</code> attribute (defined on the <a
     href="#cssconditionrule"><code>CSSConditionRule</code></a> parent rule),
@@ -1231,6 +1232,24 @@ <h3 id=the-csssupportsrule-interface><span class=secno>7.5. </span> The <a
 
   <pre class=idl>interface CSSSupportsRule : CSSConditionRule {
 }</pre>
+
+  <dl class=idl-attributes>
+   <dt><code>conditionText</code> of type <code>DOMString</code>
+    (CSSSupportsRule-specific definition for attribute on CSSConditionRule)
+
+   <dd>The <code>conditionText</code> attribute (defined on the <a
+    href="#cssconditionrule"><code>CSSConditionRule</code></a> parent rule),
+    on getting, must return the condition that was specified, without any
+    logical simplifications, so that the returned condition will evaluate to
+    the same result as the specified condition in any conformant
+    implementation of this specification (including implementations that
+    implement future extensions allowed by the <a
+    href="#general_enclosed"><i>general_enclosed</i></a> exensibility
+    mechanism in this specification). In other words, token stream
+    simplifications are allowed (such as reducing whitespace to a single
+    space or omitting it in cases where it is known to be optional), but
+    logical simplifications are not allowed.
+  </dl>
   <!--
 <h3 id="the-cssdocumentrule-interface">
 The <code>CSSDocumentRule</code> interface</h3>

css3-conditional/Overview.src.html

@@ -973,7 +973,7 @@ <h3 id="the-cssmediarule-interface">
   <dd>The <code>media</code> attribute must return a <code>MediaList</code> object
     for the list of media queries specified with the ''@media'' rule.
 
-  <dt><code>conditionText</code> of type <code>DOMString</code>
+  <dt><code>conditionText</code> of type <code>DOMString</code> (CSSMediaRule-specific definition for attribute on CSSConditionRule)
   <dd>The <code>conditionText</code> attribute (defined on the <code>CSSConditionRule</code> parent rule),
     on getting, must return the value of <code>media.mediaText</code> on the rule.
 
@@ -990,6 +990,24 @@ <h3 id="the-csssupportsrule-interface">
 <pre class='idl'>interface CSSSupportsRule : CSSConditionRule {
 }</pre>
 
+<dl class='idl-attributes'>
+  <dt><code>conditionText</code> of type <code>DOMString</code> (CSSSupportsRule-specific definition for attribute on CSSConditionRule)
+  <dd>The <code>conditionText</code> attribute (defined on the <code>CSSConditionRule</code> parent rule),
+    on getting, must return the condition that was specified,
+    without any logical simplifications,
+    so that the returned condition will evaluate to the same result
+    as the specified condition
+    in any conformant implementation of this specification
+    (including implementations that implement future extensions
+    allowed by the <i>general_enclosed</i> exensibility mechanism in this specification).
+    In other words,
+    token stream simplifications are allowed
+    (such as reducing whitespace to a single space
+    or omitting it in cases where it is known to be optional),
+    but logical simplifications are not allowed.
+
+</dl>
+
 <!--
 <h3 id="the-cssdocumentrule-interface">
 The <code>CSSDocumentRule</code> interface</h3>