[css-animations] findRule/deleteRule: apply to the last rule with the specified key value (Bug 25034)

Author: Sylvain Galineau

css-animations/Overview.bs

@@ -984,6 +984,8 @@ The <code>deleteRule</code> method</h4>
 	The <dfn method for="CSSKeyFramesRule">deleteRule()</dfn> deletes the <a idl>CSSKeyframeRule</a>
 	with the passed key. If a rule with this key does not exist, the method does nothing.
 
+	If multiple rules are specified for the passed key, the last one is deleted.
+
 	Parameters:
 
 	<dl>
@@ -1006,6 +1008,8 @@ The <code>findRule</code> method</h4>
 	The <dfn method for="CSSKeyFramesRule">findRule()</dfn> returns the rule with a key matching
 	the passed key. If no such rule exists, a null value is returned.
 
+	If multiple rules are specified for the passed key, the last one is returned.
+
 	Parameters:
 
 	<dl>

css-animations/Overview.html

@@ -999,6 +999,8 @@ <h4 class="heading settled heading" data-level=6.3.4 id=interface-csskeyframesru
 <p>	The <dfn class=idl-code data-dfn-for=CSSKeyFramesRule data-dfn-type=method data-export="" id=dom-csskeyframesrule-deleterule title=deleterule()>deleteRule()<a class=self-link href=#dom-csskeyframesrule-deleterule></a></dfn> deletes the <a data-link-type=idl href=#dom-csskeyframerule title=csskeyframerule>CSSKeyframeRule</a>
 	with the passed key. If a rule with this key does not exist, the method does nothing.
 
+<p>	If multiple rules are specified for the passed key, the last one is deleted.
+
 <p>	Parameters:
 
 	<dl>
@@ -1021,6 +1023,8 @@ <h4 class="heading settled heading" data-level=6.3.5 id=interface-csskeyframesru
 <p>	The <dfn class=idl-code data-dfn-for=CSSKeyFramesRule data-dfn-type=method data-export="" id=dom-csskeyframesrule-findrule title=findrule()>findRule()<a class=self-link href=#dom-csskeyframesrule-findrule></a></dfn> returns the rule with a key matching
 	the passed key. If no such rule exists, a null value is returned.
 
+<p>	If multiple rules are specified for the passed key, the last one is returned.
+
 <p>	Parameters:
 
 	<dl>