Bug 1305325 - Part 2: Add AnimValuesStyleRule::GetValue and HasValue to get the last composed style. r=birtles

HasValue() will be used to check that we have already composed style
for a given property or not.

MozReview-Commit-ID: L8lezGyON5o

dom/animation/AnimValuesStyleRule.cpp

@@ -83,6 +83,13 @@ AnimValuesStyleRule::AddValue(nsCSSPropertyID aProperty,
     nsCachedStyleData::GetBitForSID(nsCSSProps::kSIDTable[aProperty]);
 }
 
+bool
+AnimValuesStyleRule::GetValue(nsCSSPropertyID aProperty,
+                              StyleAnimationValue& aValue) const
+{
+  return mAnimationValues.Get(aProperty, &aValue);
+}
+
 #ifdef DEBUG
 void
 AnimValuesStyleRule::List(FILE* out, int32_t aIndent) const

dom/animation/AnimValuesStyleRule.h

@@ -45,6 +45,11 @@ public:
   void AddValue(nsCSSPropertyID aProperty, const StyleAnimationValue &aValue);
   void AddValue(nsCSSPropertyID aProperty, StyleAnimationValue&& aValue);
 
+  bool HasValue(nsCSSPropertyID aProperty) const {
+    return mAnimationValues.Contains(aProperty);
+  }
+  bool GetValue(nsCSSPropertyID aProperty, StyleAnimationValue& aValue) const;
+
 private:
   ~AnimValuesStyleRule() {}