Remove aPresContext parameter to nsStyleContext constructor and document parameters to constructor. (Bug 791416) r=bzbarsky

layout/style/nsStyleContext.cpp

@@ -33,8 +33,7 @@ using namespace mozilla;
 nsStyleContext::nsStyleContext(nsStyleContext* aParent,
                                nsIAtom* aPseudoTag,
                                nsCSSPseudoElements::Type aPseudoType,
-                               nsRuleNode* aRuleNode,
-                               nsPresContext* aPresContext)
+                               nsRuleNode* aRuleNode)
   : mParent(aParent),
     mChild(nullptr),
     mEmptyChild(nullptr),
@@ -66,7 +65,7 @@ nsStyleContext::nsStyleContext(nsStyleContext* aParent,
 #endif
   }
 
-  ApplyStyleFixups(aPresContext);
+  ApplyStyleFixups();
 
   #define eStyleStruct_LastItem (nsStyleStructID_Length - 1)
   NS_ASSERTION(NS_STYLE_INHERIT_MASK & NS_STYLE_INHERIT_BIT(LastItem),
@@ -298,7 +297,7 @@ nsStyleContext::SetStyle(nsStyleStructID aSID, void* aStruct)
 }
 
 void
-nsStyleContext::ApplyStyleFixups(nsPresContext* aPresContext)
+nsStyleContext::ApplyStyleFixups()
 {
   // See if we have any text decorations.
   // First see if our parent has text decorations.  If our parent does, then we inherit the bit.
@@ -675,12 +674,11 @@ already_AddRefed<nsStyleContext>
 NS_NewStyleContext(nsStyleContext* aParentContext,
                    nsIAtom* aPseudoTag,
                    nsCSSPseudoElements::Type aPseudoType,
-                   nsRuleNode* aRuleNode,
-                   nsPresContext* aPresContext)
+                   nsRuleNode* aRuleNode)
 {
   nsStyleContext* context =
-    new (aPresContext) nsStyleContext(aParentContext, aPseudoTag, aPseudoType,
-                                      aRuleNode, aPresContext);
+    new (aRuleNode->GetPresContext())
+      nsStyleContext(aParentContext, aPseudoTag, aPseudoType, aRuleNode);
   if (context)
     context->AddRef();
   return context;

layout/style/nsStyleContext.h

@@ -39,9 +39,27 @@ class nsPresContext;
 class nsStyleContext
 {
 public:
+  /**
+   * Create a new style context.
+   * @param aParent  The parent of a style context is used for CSS
+   *                 inheritance.  When the element or pseudo-element
+   *                 this style context represents the style data of
+   *                 inherits a CSS property, the value comes from the
+   *                 parent style context.  This means style context
+   *                 parentage must match the definitions of inheritance
+   *                 in the CSS specification.
+   * @param aPseudoTag  The pseudo-element or anonymous box for which
+   *                    this style context represents style.  Null if
+   *                    this style context is for a normal DOM element.
+   * @param aPseudoType  Must match aPseudoTag.
+   * @param aRuleNode  A rule node representing the ordered sequence of
+   *                   rules that any element, pseudo-element, or
+   *                   anonymous box that this style context is for
+   *                   matches.  See |nsRuleNode| and |nsIStyleRule|.
+   */
   nsStyleContext(nsStyleContext* aParent, nsIAtom* aPseudoTag,
                  nsCSSPseudoElements::Type aPseudoType,
-                 nsRuleNode* aRuleNode, nsPresContext* aPresContext);
+                 nsRuleNode* aRuleNode);
   ~nsStyleContext();
 
   void* operator new(size_t sz, nsPresContext* aPresContext) CPP_THROW_NEW;
@@ -323,7 +341,7 @@ protected:
   void AddChild(nsStyleContext* aChild);
   void RemoveChild(nsStyleContext* aChild);
 
-  void ApplyStyleFixups(nsPresContext* aPresContext);
+  void ApplyStyleFixups();
 
   void FreeAllocations(nsPresContext* aPresContext);
 
@@ -416,6 +434,5 @@ already_AddRefed<nsStyleContext>
 NS_NewStyleContext(nsStyleContext* aParentContext,
                    nsIAtom* aPseudoTag,
                    nsCSSPseudoElements::Type aPseudoType,
-                   nsRuleNode* aRuleNode,
-                   nsPresContext* aPresContext);
+                   nsRuleNode* aRuleNode);
 #endif

layout/style/nsStyleSet.cpp

@@ -574,13 +574,13 @@ nsStyleSet::GetContext(nsStyleContext* aParentContext,
 
   if (!result) {
     result = NS_NewStyleContext(aParentContext, aPseudoTag, aPseudoType,
-                                aRuleNode, PresContext());
+                                aRuleNode);
     if (!result)
       return nullptr;
     if (aVisitedRuleNode) {
       nsRefPtr<nsStyleContext> resultIfVisited =
         NS_NewStyleContext(parentIfVisited, aPseudoTag, aPseudoType,
-                           aVisitedRuleNode, PresContext());
+                           aVisitedRuleNode);
       if (!resultIfVisited) {
         return nullptr;
       }