Bug 1472601 - Use EnsureInserted to check a key in a hashtable and insert the key into the hashtable. r=boris

As for removing an entry, EnsureRemoved is equal to what Contains && RemoveEntry
do, but for consistency we use EnsureRemoved here.

MozReview-Commit-ID: 9qE3YtvmwC8

--HG--
extra : rebase_source : 1681194cd8b9700d46a07a502f7d2f15580918aa

dom/animation/EffectSet.cpp

@@ -151,22 +151,20 @@ EffectSet::GetEffectSetPropertyAtom(CSSPseudoElementType aPseudoType)
 void
 EffectSet::AddEffect(dom::KeyframeEffect& aEffect)
 {
-  if (mEffects.Contains(&aEffect)) {
+  if (!mEffects.EnsureInserted(&aEffect)) {
     return;
   }
 
-  mEffects.PutEntry(&aEffect);
   MarkCascadeNeedsUpdate();
 }
 
 void
 EffectSet::RemoveEffect(dom::KeyframeEffect& aEffect)
 {
-  if (!mEffects.Contains(&aEffect)) {
+  if (!mEffects.EnsureRemoved(&aEffect)) {
     return;
   }
 
-  mEffects.RemoveEntry(&aEffect);
   MarkCascadeNeedsUpdate();
 }