[cssom] Add [CEReactions] extended attributes

Things that can mutate the style="" attribute need to be annotated
for custom element callbacks. Ack @domenic.

Fixes w3c#200.

Author: zcorpan

cssom/Overview.bs

@@ -1922,17 +1922,17 @@ underlying state depends upon the source of the <code>CSSStyleDeclaration</Code>
 
 <pre class=idl>
 interface CSSStyleDeclaration {
-  attribute DOMString cssText;
+  [CEReactions] attribute DOMString cssText;
   readonly attribute unsigned long length;
   getter DOMString item(unsigned long index);
   DOMString getPropertyValue(DOMString property);
   DOMString getPropertyPriority(DOMString property);
-  void setProperty(DOMString property, [TreatNullAs=EmptyString] DOMString value, [TreatNullAs=EmptyString] optional DOMString priority = "");
-  void setPropertyValue(DOMString property, [TreatNullAs=EmptyString] DOMString value);
-  void setPropertyPriority(DOMString property, [TreatNullAs=EmptyString] DOMString priority);
-  DOMString removeProperty(DOMString property);
+  [CEReactions] void setProperty(DOMString property, [TreatNullAs=EmptyString] DOMString value, [TreatNullAs=EmptyString] optional DOMString priority = "");
+  [CEReactions] void setPropertyValue(DOMString property, [TreatNullAs=EmptyString] DOMString value);
+  [CEReactions] void setPropertyPriority(DOMString property, [TreatNullAs=EmptyString] DOMString priority);
+  [CEReactions] DOMString removeProperty(DOMString property);
   readonly attribute CSSRule? parentRule;
-  [TreatNullAs=EmptyString] attribute DOMString cssFloat;
+  [CEReactions, TreatNullAs=EmptyString] attribute DOMString cssFloat;
 };
 </pre>
 
@@ -2139,7 +2139,7 @@ is obtained by running the <a>CSS property to IDL attribute</a> algorithm for
 
 <pre class="idl extract">
 partial interface CSSStyleDeclaration {
-  [TreatNullAs=EmptyString] attribute DOMString _<var>camel_cased_attribute</var>;
+  [CEReactions, TreatNullAs=EmptyString] attribute DOMString _<var>camel_cased_attribute</var>;
 };
 </pre>
 
@@ -2163,7 +2163,7 @@ algorithm for <var>property</var>, with the <i>lowercase first</i> flag set.
 
 <pre class="idl extract">
 partial interface CSSStyleDeclaration {
-  [TreatNullAs=EmptyString] attribute DOMString _<var>webkit_cased_attribute</var>;
+  [CEReactions, TreatNullAs=EmptyString] attribute DOMString _<var>webkit_cased_attribute</var>;
 };
 </pre>
 
@@ -2188,7 +2188,7 @@ the following partial interface applies where <var>dashed attribute</var> is <va
 
 <pre class="idl">
 partial interface CSSStyleDeclaration {
-  [TreatNullAs=EmptyString] attribute DOMString _<var>dashed_attribute</var>;
+  [CEReactions, TreatNullAs=EmptyString] attribute DOMString _<var>dashed_attribute</var>;
 };
 </pre>
 
@@ -2802,6 +2802,7 @@ Brian Kardell,
 Christian Krebs,
 Daniel Glazman,
 David Baron,
+Domenic Denicola,
 <i>fantasai</i>,
 Hallvord R. M. Steen,
 Ian Hickson,