Bug 1352968 part 5 - Add a param to ctor of ServoCSSRuleList for top level list. r=heycam

@import rules can only exist in top level rule lists, and we need the
stylesheet to construct the import rules.

MozReview-Commit-ID: APCyGW8re8f

--HG--
extra : source : b9b78672249f390d56d71fa46dfa4b4cd49ef182

layout/style/GroupRule.h

@@ -79,7 +79,7 @@ struct GeckoGroupRuleRules
 struct ServoGroupRuleRules
 {
   explicit ServoGroupRuleRules(already_AddRefed<ServoCssRules> aRawRules)
-    : mRuleList(new ServoCSSRuleList(Move(aRawRules))) {}
+    : mRuleList(new ServoCSSRuleList(Move(aRawRules), nullptr)) {}
   ServoGroupRuleRules(ServoGroupRuleRules&& aOther)
     : mRuleList(Move(aOther.mRuleList)) {}
   ServoGroupRuleRules(const ServoGroupRuleRules& aCopy) {

layout/style/ServoCSSRuleList.cpp

@@ -22,8 +22,10 @@
 
 namespace mozilla {
 
-ServoCSSRuleList::ServoCSSRuleList(already_AddRefed<ServoCssRules> aRawRules)
-  : mRawRules(aRawRules)
+ServoCSSRuleList::ServoCSSRuleList(already_AddRefed<ServoCssRules> aRawRules,
+                                   ServoStyleSheet* aDirectOwnerStyleSheet)
+  : mStyleSheet(aDirectOwnerStyleSheet)
+  , mRawRules(aRawRules)
 {
   Servo_CssRules_ListTypes(mRawRules, &mRules);
   // XXX We may want to eagerly create object for import rule, so that

layout/style/ServoCSSRuleList.h

@@ -25,7 +25,12 @@ class Rule;
 class ServoCSSRuleList final : public dom::CSSRuleList
 {
 public:
-  explicit ServoCSSRuleList(already_AddRefed<ServoCssRules> aRawRules);
+  // @param aDirectOwnerStyleSheet should be set to the owner stylesheet
+  // if this rule list is owned directly by a stylesheet, which means it
+  // is a top level CSSRuleList. If it's owned by a group rule, nullptr.
+  // If this param is set, the caller doesn't need to call SetStyleSheet.
+  ServoCSSRuleList(already_AddRefed<ServoCssRules> aRawRules,
+                   ServoStyleSheet* aDirectOwnerStyleSheet);
   css::GroupRule* GetParentRule() const { return mParentRule; }
   void SetParentRule(css::GroupRule* aParentRule);
   void SetStyleSheet(StyleSheet* aSheet);

layout/style/ServoStyleSheet.cpp

@@ -221,8 +221,7 @@ ServoStyleSheet::GetCssRulesInternal(ErrorResult& aRv)
     RefPtr<ServoCssRules> rawRules =
       Servo_StyleSheet_GetRules(Inner()->mSheet).Consume();
     MOZ_ASSERT(rawRules);
-    mRuleList = new ServoCSSRuleList(rawRules.forget());
-    mRuleList->SetStyleSheet(this);
+    mRuleList = new ServoCSSRuleList(rawRules.forget(), this);
   }
   return mRuleList;
 }