Bug 846972 part 2. Add the WebIDL APIs for StyleSheet and CSSStyleSheet. r=peterv

content/base/public/nsIStyleSheetLinkingElement.h

@@ -16,6 +16,7 @@ class nsIURI;
  { 0xb2, 0xe9, 0x63, 0x52, 0x8c, 0x87, 0x99, 0x7a } }
 
 class nsIStyleSheet;
+class nsCSSStyleSheet;
 
 class nsIStyleSheetLinkingElement : public nsISupports {
 public:
@@ -28,7 +29,7 @@ public:
    * @param aStyleSheet the style sheet associated with this
    *                    element.
    */
-  NS_IMETHOD SetStyleSheet(nsIStyleSheet* aStyleSheet) = 0;
+  NS_IMETHOD SetStyleSheet(nsCSSStyleSheet* aStyleSheet) = 0;
 
   /**
    * Used to obtain the style sheet linked in by this element.

content/base/src/nsStyleLinkElement.cpp

@@ -56,21 +56,17 @@ nsStyleLinkElement::Traverse(nsCycleCollectionTraversalCallback &cb)
 }
 
 NS_IMETHODIMP 
-nsStyleLinkElement::SetStyleSheet(nsIStyleSheet* aStyleSheet)
+nsStyleLinkElement::SetStyleSheet(nsCSSStyleSheet* aStyleSheet)
 {
-  nsRefPtr<nsCSSStyleSheet> cssSheet = do_QueryObject(mStyleSheet);
-  if (cssSheet) {
-    cssSheet->SetOwningNode(nullptr);
+  if (mStyleSheet) {
+    mStyleSheet->SetOwningNode(nullptr);
   }
 
   mStyleSheet = aStyleSheet;
-  cssSheet = do_QueryObject(mStyleSheet);
-  if (cssSheet) {
-    nsCOMPtr<nsIDOMNode> node;
-    CallQueryInterface(this,
-                       static_cast<nsIDOMNode**>(getter_AddRefs(node)));
+  if (mStyleSheet) {
+    nsCOMPtr<nsINode> node = do_QueryObject(this);
     if (node) {
-      cssSheet->SetOwningNode(node);
+      mStyleSheet->SetOwningNode(node);
     }
   }
     
@@ -97,15 +93,7 @@ nsStyleLinkElement::InitStyleLinkElement(bool aDontLoadStyle)
 NS_IMETHODIMP
 nsStyleLinkElement::GetSheet(nsIDOMStyleSheet** aSheet)
 {
-  NS_ENSURE_ARG_POINTER(aSheet);
-  *aSheet = nullptr;
-
-  if (mStyleSheet) {
-    CallQueryInterface(mStyleSheet, aSheet);
-  }
-
-  // Always return NS_OK to avoid throwing JS exceptions if mStyleSheet 
-  // is not a nsIDOMStyleSheet
+  NS_IF_ADDREF(*aSheet = mStyleSheet);
   return NS_OK;
 }
 
@@ -416,14 +404,10 @@ nsStyleLinkElement::UpdateStyleSheetScopedness(bool aIsNowScoped)
     return;
   }
 
-  nsRefPtr<nsCSSStyleSheet> cssStyleSheet = do_QueryObject(mStyleSheet);
-  NS_ASSERTION(cssStyleSheet, "should only call UpdateStyleSheetScope for "
-                              "an nsCSSStyleSheet");
-
   nsCOMPtr<nsIContent> thisContent;
   CallQueryInterface(this, getter_AddRefs(thisContent));
 
-  Element* oldScopeElement = cssStyleSheet->GetScopeElement();
+  Element* oldScopeElement = mStyleSheet->GetScopeElement();
   Element* newScopeElement = aIsNowScoped ?
                                thisContent->GetParentElement() :
                                nullptr;
@@ -437,7 +421,7 @@ nsStyleLinkElement::UpdateStyleSheetScopedness(bool aIsNowScoped)
   document->BeginUpdate(UPDATE_STYLE);
   document->RemoveStyleSheet(mStyleSheet);
 
-  cssStyleSheet->SetScopeElement(newScopeElement);
+  mStyleSheet->SetScopeElement(newScopeElement);
 
   document->AddStyleSheet(mStyleSheet);
   document->EndUpdate(UPDATE_STYLE);

content/base/src/nsStyleLinkElement.h

@@ -16,7 +16,7 @@
 #include "nsCOMPtr.h"
 #include "nsIDOMLinkStyle.h"
 #include "nsIStyleSheetLinkingElement.h"
-#include "nsIStyleSheet.h"
+#include "nsCSSStyleSheet.h"
 #include "nsIURI.h"
 #include "nsTArray.h"
 #include "mozilla/CORSMode.h"
@@ -41,10 +41,10 @@ public:
   // nsIDOMLinkStyle
   NS_DECL_NSIDOMLINKSTYLE
 
-  nsIStyleSheet* GetSheet() { return mStyleSheet; }
+  nsCSSStyleSheet* GetSheet() const { return mStyleSheet; }
 
   // nsIStyleSheetLinkingElement  
-  NS_IMETHOD SetStyleSheet(nsIStyleSheet* aStyleSheet);
+  NS_IMETHOD SetStyleSheet(nsCSSStyleSheet* aStyleSheet);
   NS_IMETHOD GetStyleSheet(nsIStyleSheet*& aStyleSheet);
   NS_IMETHOD InitStyleLinkElement(bool aDontLoadStyle);
   NS_IMETHOD UpdateStyleSheet(nsICSSLoaderObserver* aObserver,
@@ -105,7 +105,7 @@ private:
                               bool* aIsAlternate,
                               bool aForceUpdate);
 
-  nsCOMPtr<nsIStyleSheet> mStyleSheet;
+  nsRefPtr<nsCSSStyleSheet> mStyleSheet;
 protected:
   bool mDontLoadStyle;
   bool mUpdatesEnabled;

content/html/content/src/HTMLLinkElement.cpp

@@ -69,43 +69,34 @@ NS_HTML_CONTENT_INTERFACE_MAP_END
 NS_IMPL_ELEMENT_CLONE(HTMLLinkElement)
 
 bool
-HTMLLinkElement::GetDisabled(ErrorResult& aRv)
+HTMLLinkElement::Disabled()
 {
-  nsCOMPtr<nsIDOMStyleSheet> ss = do_QueryInterface(GetSheet());
-  if (!ss) {
-    return false;
-  }
-
-  bool disabled = false;
-  aRv = ss->GetDisabled(&disabled);
-  return disabled;
+  nsCSSStyleSheet* ss = GetSheet();
+  return ss && ss->Disabled();
 }
 
 NS_IMETHODIMP
-HTMLLinkElement::GetDisabled(bool* aDisabled)
+HTMLLinkElement::GetMozDisabled(bool* aDisabled)
 {
-  ErrorResult rv;
-  *aDisabled = GetDisabled(rv);
-  return rv.ErrorCode();
+  *aDisabled = Disabled();
+  return NS_OK;
 }
 
 void
-HTMLLinkElement::SetDisabled(bool aDisabled, ErrorResult& aRv)
+HTMLLinkElement::SetDisabled(bool aDisabled)
 {
-  nsCOMPtr<nsIDOMStyleSheet> ss = do_QueryInterface(GetSheet());
-  if (!ss) {
-    return;
+  nsCSSStyleSheet* ss = GetSheet();
+  if (ss) {
+    ss->SetDisabled(aDisabled);
   }
 
-  aRv = ss->SetDisabled(aDisabled);
 }
 
 NS_IMETHODIMP
-HTMLLinkElement::SetDisabled(bool aDisabled)
+HTMLLinkElement::SetMozDisabled(bool aDisabled)
 {
-  ErrorResult rv;
-  SetDisabled(aDisabled, rv);
-  return rv.ErrorCode();
+  SetDisabled(aDisabled);
+  return NS_OK;
 }
 
 

content/html/content/src/HTMLLinkElement.h

@@ -92,8 +92,8 @@ public:
   void CreateAndDispatchEvent(nsIDocument* aDoc, const nsAString& aEventName);
 
   // WebIDL
-  bool GetDisabled(ErrorResult& aRv);
-  void SetDisabled(bool aDisabled, ErrorResult& aRv);
+  bool Disabled();
+  void SetDisabled(bool aDisabled);
   // XPCOM GetHref is fine.
   void SetHref(const nsAString& aHref, ErrorResult& aRv)
   {

content/html/content/src/HTMLStyleElement.cpp

@@ -61,7 +61,7 @@ NS_IMPL_ELEMENT_CLONE(HTMLStyleElement)
 
 
 NS_IMETHODIMP
-HTMLStyleElement::GetDisabled(bool* aDisabled)
+HTMLStyleElement::GetMozDisabled(bool* aDisabled)
 {
   NS_ENSURE_ARG_POINTER(aDisabled);
 
@@ -72,36 +72,23 @@ HTMLStyleElement::GetDisabled(bool* aDisabled)
 bool
 HTMLStyleElement::Disabled()
 {
-  nsCOMPtr<nsIDOMStyleSheet> ss = do_QueryInterface(GetSheet());
-  if (!ss) {
-    return false;
-  }
-
-  bool disabled = false;
-  ss->GetDisabled(&disabled);
-
-  return disabled;
+  nsCSSStyleSheet* ss = GetSheet();
+  return ss && ss->Disabled();
 }
 
 NS_IMETHODIMP
-HTMLStyleElement::SetDisabled(bool aDisabled)
+HTMLStyleElement::SetMozDisabled(bool aDisabled)
 {
-  ErrorResult error;
-  SetDisabled(aDisabled, error);
-  return error.ErrorCode();
+  SetDisabled(aDisabled);
+  return NS_OK;
 }
 
 void
-HTMLStyleElement::SetDisabled(bool aDisabled, ErrorResult& aError)
+HTMLStyleElement::SetDisabled(bool aDisabled)
 {
-  nsCOMPtr<nsIDOMStyleSheet> ss = do_QueryInterface(GetSheet());
-  if (!ss) {
-    return;
-  }
-
-  nsresult result = ss->SetDisabled(aDisabled);
-  if (NS_FAILED(result)) {
-    aError.Throw(result);
+  nsCSSStyleSheet* ss = GetSheet();
+  if (ss) {
+    ss->SetDisabled(aDisabled);
   }
 }
 

content/html/content/src/HTMLStyleElement.h

@@ -74,7 +74,7 @@ public:
   NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
 
   bool Disabled();
-  void SetDisabled(bool aDisabled, ErrorResult& aError);
+  void SetDisabled(bool aDisabled);
   void SetMedia(const nsAString& aMedia, ErrorResult& aError)
   {
     SetHTMLAttr(nsGkAtoms::media, aMedia, aError);

dom/bindings/BindingDeclarations.h

@@ -21,6 +21,12 @@
 #include "nsStringBuffer.h"
 #include "nsTArray.h"
 
+class nsWrapperCache;
+
+// nsGlobalWindow implements nsWrapperCache, but doesn't always use it. Don't
+// try to use it without fixing that first.
+class nsGlobalWindow;
+
 namespace mozilla {
 namespace dom {
 
@@ -379,6 +385,52 @@ private:
   JSContext* mCx;
 };
 
+inline nsWrapperCache*
+GetWrapperCache(nsWrapperCache* cache)
+{
+  return cache;
+}
+
+inline nsWrapperCache*
+GetWrapperCache(nsGlobalWindow* not_allowed);
+
+inline nsWrapperCache*
+GetWrapperCache(void* p)
+{
+  return NULL;
+}
+
+// Helper template for smart pointers to resolve ambiguity between
+// GetWrappeCache(void*) and GetWrapperCache(const ParentObject&).
+template <template <typename> class SmartPtr, typename T>
+inline nsWrapperCache*
+GetWrapperCache(const SmartPtr<T>& aObject)
+{
+  return GetWrapperCache(aObject.get());
+}
+
+struct ParentObject {
+  template<class T>
+  ParentObject(T* aObject) :
+    mObject(aObject),
+    mWrapperCache(GetWrapperCache(aObject))
+  {}
+
+  template<class T, template<typename> class SmartPtr>
+  ParentObject(const SmartPtr<T>& aObject) :
+    mObject(aObject.get()),
+    mWrapperCache(GetWrapperCache(aObject.get()))
+  {}
+
+  ParentObject(nsISupports* aObject, nsWrapperCache* aCache) :
+    mObject(aObject),
+    mWrapperCache(aCache)
+  {}
+
+  nsISupports* const mObject;
+  nsWrapperCache* const mWrapperCache;
+};
+
 } // namespace dom
 } // namespace mozilla
 

dom/bindings/BindingUtils.h

@@ -25,10 +25,6 @@
 #include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/CallbackObject.h"
 
-// nsGlobalWindow implements nsWrapperCache, but doesn't always use it. Don't
-// try to use it without fixing that first.
-class nsGlobalWindow;
-
 namespace mozilla {
 namespace dom {
 
@@ -682,30 +678,6 @@ NativeInterface2JSObjectAndThrowIfFailed(JSContext* aCx,
                                          const nsIID* aIID,
                                          bool aAllowNativeWrapper);
 
-inline nsWrapperCache*
-GetWrapperCache(nsWrapperCache* cache)
-{
-  return cache;
-}
-
-inline nsWrapperCache*
-GetWrapperCache(nsGlobalWindow* not_allowed);
-
-inline nsWrapperCache*
-GetWrapperCache(void* p)
-{
-  return NULL;
-}
-
-// Helper template for smart pointers to resolve ambiguity between
-// GetWrappeCache(void*) and GetWrapperCache(const ParentObject&).
-template <template <typename> class SmartPtr, typename T>
-inline nsWrapperCache*
-GetWrapperCache(const SmartPtr<T>& aObject)
-{
-  return GetWrapperCache(aObject.get());
-}
-
 /**
  * A method to handle new-binding wrap failure, by possibly falling back to
  * wrapping as a non-new-binding object.
@@ -827,28 +799,6 @@ FindEnumStringIndex(JSContext* cx, JS::Value v, const EnumEntry* values,
   return -1;
 }
 
-struct ParentObject {
-  template<class T>
-  ParentObject(T* aObject) :
-    mObject(aObject),
-    mWrapperCache(GetWrapperCache(aObject))
-  {}
-
-  template<class T, template<typename> class SmartPtr>
-  ParentObject(const SmartPtr<T>& aObject) :
-    mObject(aObject.get()),
-    mWrapperCache(GetWrapperCache(aObject.get()))
-  {}
-
-  ParentObject(nsISupports* aObject, nsWrapperCache* aCache) :
-    mObject(aObject),
-    mWrapperCache(aCache)
-  {}
-
-  nsISupports* const mObject;
-  nsWrapperCache* const mWrapperCache;
-};
-
 inline nsWrapperCache*
 GetWrapperCache(const ParentObject& aParentObject)
 {

dom/interfaces/html/nsIDOMHTMLLinkElement.idl

@@ -19,6 +19,7 @@
 [scriptable, uuid(ca856a0b-6786-4123-90fe-dc9c7600274e)]
 interface nsIDOMHTMLLinkElement : nsIDOMHTMLElement
 {
+           [binaryname(MozDisabled)]
            attribute boolean          disabled;
            attribute DOMString        charset;
            attribute DOMString        href;

dom/interfaces/html/nsIDOMHTMLStyleElement.idl

@@ -19,6 +19,7 @@
 [scriptable, uuid(5e6c9cac-5594-4006-ae3f-ad82fb28cee9)]
 interface nsIDOMHTMLStyleElement : nsIDOMHTMLElement
 {
+           [binaryname(MozDisabled)]
            attribute boolean          disabled;
            attribute DOMString        media;
            attribute DOMString        type;

dom/webidl/CSSStyleSheet.webidl

@@ -0,0 +1,22 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origin of this IDL file is
+ * http://dev.w3.org/csswg/cssom/
+ */
+
+interface CSSRuleList;
+interface CSSRule;
+
+interface CSSStyleSheet : StyleSheet {
+  [Pure]
+  readonly attribute CSSRule? ownerRule;
+  [Throws]
+  readonly attribute CSSRuleList cssRules;
+  [Throws]
+  unsigned long insertRule(DOMString rule, unsigned long index);
+  [Throws]
+  void deleteRule(unsigned long index);
+};

dom/webidl/HTMLLinkElement.webidl

@@ -13,7 +13,7 @@
 
 // http://www.whatwg.org/specs/web-apps/current-work/#the-link-element
 interface HTMLLinkElement : HTMLElement {
-  [Throws]
+  [Pure]
            attribute boolean disabled;
   [SetterThrows, Pure]
            attribute DOMString href;

dom/webidl/HTMLStyleElement.webidl

@@ -9,13 +9,13 @@
  */
 
 interface HTMLStyleElement : HTMLElement {
-           [SetterThrows]
+           [Pure]
            attribute boolean disabled;
-           [SetterThrows]
+           [SetterThrows, Pure]
            attribute DOMString media;
-           [SetterThrows]
+           [SetterThrows, Pure]
            attribute DOMString type;
-           [SetterThrows]
+           [SetterThrows, Pure]
            attribute boolean scoped;
 };
 HTMLStyleElement implements LinkStyle;

dom/webidl/StyleSheet.webidl

@@ -0,0 +1,30 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origin of this IDL file is
+ * http://dev.w3.org/csswg/cssom/
+ */
+
+interface CSSRule;
+interface MediaList;
+
+interface StyleSheet {
+  [Constant]
+  readonly attribute DOMString type;
+  [Constant]
+  readonly attribute DOMString? href;
+  // Spec says "Node", but it can go null when the node gets a new
+  // sheet.  That's also why it's not [Constant]
+  [Pure]
+  readonly attribute Node? ownerNode;
+  [Pure]
+  readonly attribute StyleSheet? parentStyleSheet;
+  [Pure]
+  readonly attribute DOMString? title;
+  [Constant]
+  readonly attribute MediaList media;
+  [Pure]
+  attribute boolean disabled;
+};

layout/style/Loader.cpp

@@ -2424,7 +2424,7 @@ CountSheetMemory(URIPrincipalAndCORSModeHashKey* /* unused */,
   // have to worry about it here.
   // Likewise, if aSheet has an owning node, then the document that
   // node is in will report it.
-  if (aSheet->GetOwningNode() || aSheet->GetParentSheet()) {
+  if (aSheet->GetOwnerNode() || aSheet->GetParentSheet()) {
     return 0;
   }
   return aSheet->SizeOfIncludingThis(aMallocSizeOf);

layout/style/nsCSSStyleSheet.cpp

@@ -554,12 +554,7 @@ nsMediaList::SetText(const nsAString& aMediaText)
 {
   nsCSSParser parser;
 
-  bool htmlMode = false;
-  if (mStyleSheet) {
-    nsCOMPtr<nsIDOMNode> node;
-    mStyleSheet->GetOwnerNode(getter_AddRefs(node));
-    htmlMode = !!node;
-  }
+  bool htmlMode = mStyleSheet && mStyleSheet->GetOwnerNode();
 
   return parser.ParseMediaList(aMediaText, nullptr, 0,
                                this, htmlMode);
@@ -1044,7 +1039,7 @@ nsCSSStyleSheet::nsCSSStyleSheet(const nsCSSStyleSheet& aCopy,
                                  nsCSSStyleSheet* aParentToUse,
                                  css::ImportRule* aOwnerRuleToUse,
                                  nsIDocument* aDocumentToUse,
-                                 nsIDOMNode* aOwningNodeToUse)
+                                 nsINode* aOwningNodeToUse)
   : mTitle(aCopy.mTitle),
     mParent(aParentToUse),
     mOwnerRule(aOwnerRuleToUse),
@@ -1383,8 +1378,7 @@ nsCSSStyleSheet::FindOwningWindowInnerID() const
   }
 
   if (windowID == 0 && mOwningNode) {
-    nsCOMPtr<nsINode> node = do_QueryInterface(mOwningNode);
-    windowID = node->OwnerDoc()->InnerWindowID();
+    windowID = mOwningNode->OwnerDoc()->InnerWindowID();
   }
 
   if (windowID == 0 && mOwnerRule) {
@@ -1582,7 +1576,7 @@ already_AddRefed<nsCSSStyleSheet>
 nsCSSStyleSheet::Clone(nsCSSStyleSheet* aCloneParent,
                        css::ImportRule* aCloneOwnerRule,
                        nsIDocument* aCloneDocument,
-                       nsIDOMNode* aCloneOwningNode) const
+                       nsINode* aCloneOwningNode) const
 {
   nsCSSStyleSheet* clone = new nsCSSStyleSheet(*this,
                                                aCloneParent,
@@ -1757,7 +1751,7 @@ nsCSSStyleSheet::GetType(nsAString& aType)
 NS_IMETHODIMP    
 nsCSSStyleSheet::GetDisabled(bool* aDisabled)
 {
-  *aDisabled = mDisabled;
+  *aDisabled = Disabled();
   return NS_OK;
 }
 
@@ -1773,8 +1767,8 @@ nsCSSStyleSheet::SetDisabled(bool aDisabled)
 NS_IMETHODIMP
 nsCSSStyleSheet::GetOwnerNode(nsIDOMNode** aOwnerNode)
 {
-  *aOwnerNode = mOwningNode;
-  NS_IF_ADDREF(*aOwnerNode);
+  nsCOMPtr<nsIDOMNode> ownerNode = do_QueryInterface(GetOwnerNode());
+  ownerNode.forget(aOwnerNode);
   return NS_OK;
 }
 
@@ -1818,53 +1812,66 @@ nsCSSStyleSheet::GetTitle(nsAString& aTitle)
 NS_IMETHODIMP
 nsCSSStyleSheet::GetMedia(nsIDOMMediaList** aMedia)
 {
-  NS_ENSURE_ARG_POINTER(aMedia);
-  *aMedia = nullptr;
+  NS_ADDREF(*aMedia = Media());
+  return NS_OK;
+}
 
+nsIDOMMediaList*
+nsCSSStyleSheet::Media()
+{
   if (!mMedia) {
     mMedia = new nsMediaList();
-    NS_ENSURE_TRUE(mMedia, NS_ERROR_OUT_OF_MEMORY);
     mMedia->SetStyleSheet(this);
   }
 
-  *aMedia = mMedia;
-  NS_ADDREF(*aMedia);
-
-  return NS_OK;
+  return mMedia;
 }
 
 NS_IMETHODIMP    
 nsCSSStyleSheet::GetOwnerRule(nsIDOMCSSRule** aOwnerRule)
 {
-  if (mOwnerRule) {
-    NS_IF_ADDREF(*aOwnerRule = mOwnerRule->GetDOMRule());
-  } else {
-    *aOwnerRule = nullptr;
-  }
+  NS_IF_ADDREF(*aOwnerRule = GetOwnerRule());
   return NS_OK;
 }
 
+nsIDOMCSSRule*
+nsCSSStyleSheet::GetDOMOwnerRule() const
+{
+  return mOwnerRule ? mOwnerRule->GetDOMRule() : nullptr;
+}
+
 NS_IMETHODIMP    
 nsCSSStyleSheet::GetCssRules(nsIDOMCSSRuleList** aCssRules)
+{
+  ErrorResult rv;
+  nsCOMPtr<nsIDOMCSSRuleList> rules = GetCssRules(rv);
+  rules.forget(aCssRules);
+  return rv.ErrorCode();
+}
+
+nsIDOMCSSRuleList*
+nsCSSStyleSheet::GetCssRules(ErrorResult& aRv)
 {
   // No doing this on incomplete sheets!
   if (!mInner->mComplete) {
-    return NS_ERROR_DOM_INVALID_ACCESS_ERR;
+    aRv.Throw(NS_ERROR_DOM_INVALID_ACCESS_ERR);
+    return nullptr;
   }
   
   //-- Security check: Only scripts whose principal subsumes that of the
   //   style sheet can access rule collections.
   nsresult rv = SubjectSubsumesInnerPrincipal();
-  NS_ENSURE_SUCCESS(rv, rv);
+  if (NS_FAILED(rv)) {
+    aRv.Throw(rv);
+    return nullptr;
+  }
 
   // OK, security check passed, so get the rule collection
-  if (nullptr == mRuleCollection) {
+  if (!mRuleCollection) {
     mRuleCollection = new CSSRuleListImpl(this);
   }
 
-  NS_ADDREF(*aCssRules = mRuleCollection);
-
-  return NS_OK;
+  return mRuleCollection;
 }
 
 NS_IMETHODIMP    

layout/style/nsCSSStyleSheet.h

@@ -176,8 +176,7 @@ public:
 
   void SetTitle(const nsAString& aTitle) { mTitle = aTitle; }
   void SetMedia(nsMediaList* aMedia);
-  void SetOwningNode(nsIDOMNode* aOwningNode) { mOwningNode = aOwningNode; /* Not ref counted */ }
-  nsIDOMNode* GetOwningNode() const { return mOwningNode; }
+  void SetOwningNode(nsINode* aOwningNode) { mOwningNode = aOwningNode; /* Not ref counted */ }
 
   void SetOwnerRule(mozilla::css::ImportRule* aOwnerRule) { mOwnerRule = aOwnerRule; /* Not ref counted */ }
   mozilla::css::ImportRule* GetOwnerRule() const { return mOwnerRule; }
@@ -187,7 +186,7 @@ public:
   already_AddRefed<nsCSSStyleSheet> Clone(nsCSSStyleSheet* aCloneParent,
                                           mozilla::css::ImportRule* aCloneOwnerRule,
                                           nsIDocument* aCloneDocument,
-                                          nsIDOMNode* aCloneOwningNode) const;
+                                          nsINode* aCloneOwningNode) const;
 
   bool IsModified() const { return mDirty; }
 
@@ -255,12 +254,56 @@ public:
     mScopeElement = aScopeElement;
   }
 
+  // WebIDL StyleSheet API
+  // Our nsIStyleSheet::GetType is a const method, so it ends up
+  // ambiguous with with the XPCOM version.  Just disambiguate.
+  void GetType(nsString& aType) {
+    const_cast<const nsCSSStyleSheet*>(this)->GetType(aType);
+  }
+  // Our XPCOM GetHref is fine for WebIDL
+  nsINode* GetOwnerNode() const { return mOwningNode; }
+  nsCSSStyleSheet* GetParentStyleSheet() const { return mParent; }
+  // Our nsIStyleSheet::GetTitle is a const method, so it ends up
+  // ambiguous with with the XPCOM version.  Just disambiguate.
+  void GetTitle(nsString& aTitle) {
+    const_cast<const nsCSSStyleSheet*>(this)->GetTitle(aTitle);
+  }
+  nsIDOMMediaList* Media();
+  bool Disabled() const { return mDisabled; }
+  // The XPCOM SetDisabled is fine for WebIDL
+
+  // WebIDL CSSStyleSheet API
+  // Can't be inline because we can't include ImportRule here.  And can't be
+  // called GetOwnerRule because that would be ambiguous with the ImportRule
+  // version.
+  nsIDOMCSSRule* GetDOMOwnerRule() const;
+  nsIDOMCSSRuleList* GetCssRules(mozilla::ErrorResult& aRv);
+  uint32_t InsertRule(const nsAString& aRule, uint32_t aIndex,
+                      mozilla::ErrorResult& aRv) {
+    uint32_t retval;
+    aRv = InsertRule(aRule, aIndex, &retval);
+    return retval;
+  }
+  void DeleteRule(uint32_t aIndex, mozilla::ErrorResult& aRv) {
+    aRv = DeleteRule(aIndex);
+  }
+
+  // WebIDL miscellaneous bits
+  mozilla::dom::ParentObject GetParentObject() const {
+    if (mOwningNode) {
+      return mozilla::dom::ParentObject(mOwningNode);
+    }
+
+    return mozilla::dom::ParentObject(static_cast<nsIStyleSheet*>(mParent),
+                                      mParent);
+  }
+
 private:
   nsCSSStyleSheet(const nsCSSStyleSheet& aCopy,
                   nsCSSStyleSheet* aParentToUse,
                   mozilla::css::ImportRule* aOwnerRuleToUse,
                   nsIDocument* aDocumentToUse,
-                  nsIDOMNode* aOwningNodeToUse);
+                  nsINode* aOwningNodeToUse);
 
   nsCSSStyleSheet(const nsCSSStyleSheet& aCopy) MOZ_DELETE;
   nsCSSStyleSheet& operator=(const nsCSSStyleSheet& aCopy) MOZ_DELETE;
@@ -302,7 +345,7 @@ protected:
 
   nsRefPtr<CSSRuleListImpl> mRuleCollection;
   nsIDocument*          mDocument; // weak ref; parents maintain this for their children
-  nsIDOMNode*           mOwningNode; // weak ref
+  nsINode*              mOwningNode; // weak ref
   bool                  mDisabled;
   bool                  mDirty; // has been modified 
   nsRefPtr<mozilla::dom::Element> mScopeElement;