[css-animations-1] Animations are only canceled if base and computed display are none. (w3c#8713)

Author: flackr

css-animations-2/Overview.bs

@@ -154,6 +154,17 @@ The <dfn>owning element</dfn> of an animation refers to the element or
 pseudo-element to which the 'animation-name' property was applied that generated
 the animation.
 
+If the 'display' property of an element is set to ''display/none''
+and its 'display' value would compute to ''display/none'' when ignoring the Transitions and Animations [=cascade origins=],
+then terminate running animations with this <a>owning element</a>.
+If an element has a 'display' of ''display/none'' and
+its 'display' value had computed to ''display/none'' when ignoring the Transitions and Animations [=cascade origins=],
+updating 'display' to a value other than ''display/none''
+will start all animations applied to the element by the 'animation-name' property.
+
+Note: In practice, this means that an animation to a 'display' value of ''display/none'' will not terminate running animations
+unless the style also computes to ''display/none'' without the effect of the animations.
+
 If an animation generated using the markup defined in this specification is
 later disassociated from that markup by an update to the computed value of the
 'animation-name' property on the <a>owning element</a>, the animation is
@@ -597,7 +608,7 @@ Initial: auto
 Applies to: all elements
 Inherited: no
 Percentages: N/A
-Computed value: list, each item either a case-sensitive [=css identifier=] or 
+Computed value: list, each item either a case-sensitive [=css identifier=] or
     the keywords ''single-animation-timeline/none'',
     ''single-animation-timeline/auto''.
 Canonical order: per grammar
@@ -877,12 +888,12 @@ console.log(anim.playState); // Should be 'running'.
 
 <h2 id="priv">
   Privacy Considerations</h2>
-  
+
   No privacy concerns have been reported on this specification.
-  
+
   <h2 id="sec">
   Security Considerations</h2>
-    
+
   No security concerns have been reported on this specification.
 
 <h2 id="changes">Changes</h2>
@@ -891,8 +902,8 @@ console.log(anim.playState); // Should be 'running'.
 
 <ul>
   <li>
-    The interaction between CSS Animations and Web Animations is defined, 
-    and the concepts of the owning element and animation composite order 
+    The interaction between CSS Animations and Web Animations is defined,
+    and the concepts of the owning element and animation composite order
     are introduced.
   </li>
   <li>

css-display-4/Overview.bs

@@ -874,11 +874,6 @@ Animating and Interpolating 'display'</h3>
 	as long as its 'display' value would compute to ''display/none''
 	when ignoring the Transitions and Animations [=cascade origins=].
 
-	Because a value of ''display/none'' would interrupt the animation,
-	a declared value of ''display/none''
-	in an <a spec=web-animations-1>animation effect</a> or ''@keyframes'' rule
-	is replaced with ''display/revert-layer''.
-
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