Bug 1274944 - Part 1: Add writable spacing attribute. r=smaug

Use [SetterThrows] for KeyframeEffect.spacing because it throws if the input
string is not conformed to the grammar.

MozReview-Commit-ID: CkAnPu8TnV

--HG--
extra : rebase_source : af0960391684323a25ac0b40da28dcbe5c3c2919

dom/animation/KeyframeEffect.cpp

@@ -125,5 +125,13 @@ KeyframeEffect::SetTarget(const Nullable<ElementOrCSSPseudoElement>& aTarget)
   }
 }
 
+void
+KeyframeEffect::SetSpacing(JSContext* aCx,
+                           const nsAString& aSpacing,
+                           ErrorResult& aRv)
+{
+  // TODO: Implement this in the next patch.
+}
+
 } // namespace dom
 } // namespace mozilla

dom/animation/KeyframeEffect.h

@@ -65,6 +65,8 @@ public:
   // that to update the properties rather than calling
   // GetStyleContextForElement.
   void SetTarget(const Nullable<ElementOrCSSPseudoElement>& aTarget);
+
+  void SetSpacing(JSContext* aCx, const nsAString& aSpacing, ErrorResult& aRv);
 };
 
 } // namespace dom

dom/bindings/Bindings.conf

@@ -624,6 +624,10 @@ DOMInterfaces = {
     'concrete': False
 },
 
+'KeyframeEffect': {
+    'implicitJSContext': { 'setterOnly': [ 'spacing' ] }
+},
+
 'LegacyMozTCPSocket': {
     'headerFile': 'TCPSocket.h',
     'wrapperCache': False,

dom/webidl/KeyframeEffect.webidl

@@ -73,8 +73,8 @@ interface KeyframeEffect : KeyframeEffectReadOnly {
   // inherit attribute IterationCompositeOperation iterationComposite;
   // Bug 1216844 - implement additive animation
   // inherit attribute CompositeOperation          composite;
-  // Bug 1244590 - implement spacing modes
-  // inherit attribute DOMString                   spacing;
+  [SetterThrows]
+  inherit attribute DOMString                   spacing;
   [Throws]
   void setKeyframes (object? keyframes);
 };