Issue #2490 - Part 11: Convert CSSImportRule to WebIDL.

Note that the .media PutForwards is a new feature coming along for the ride, now
that we're using the spec IDL.

dom/base/nsDOMClassInfo.cpp

@@ -74,7 +74,6 @@
 // includes needed for the prototype chain interfaces
 #include "nsIDOMCSSKeyframeRule.h"
 #include "nsIDOMCSSKeyframesRule.h"
-#include "nsIDOMCSSImportRule.h"
 #include "nsIDOMCSSMediaRule.h"
 #include "nsIDOMCSSFontFaceRule.h"
 #include "nsIDOMCSSMozDocumentRule.h"
@@ -192,9 +191,6 @@ static nsDOMClassInfoData sClassInfoData[] = {
   NS_DEFINE_CLASSINFO_DATA(CSSStyleRule, nsCSSRuleSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS |
                            nsIXPCScriptable::WANT_PRECREATE)
-  NS_DEFINE_CLASSINFO_DATA(CSSImportRule, nsCSSRuleSH,
-                           DOM_DEFAULT_SCRIPTABLE_FLAGS |
-                           nsIXPCScriptable::WANT_PRECREATE)
   NS_DEFINE_CLASSINFO_DATA(CSSMediaRule, nsCSSRuleSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS |
                            nsIXPCScriptable::WANT_PRECREATE)
@@ -525,11 +521,6 @@ nsDOMClassInfo::Init()
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMCSSStyleRule)
   DOM_CLASSINFO_MAP_END
 
-  DOM_CLASSINFO_MAP_BEGIN(CSSImportRule, nsIDOMCSSImportRule)
-    DOM_CLASSINFO_MAP_ENTRY(nsIDOMCSSRule)
-    DOM_CLASSINFO_MAP_ENTRY(nsIDOMCSSImportRule)
-  DOM_CLASSINFO_MAP_END
-
   DOM_CLASSINFO_MAP_BEGIN(CSSMediaRule, nsIDOMCSSMediaRule)
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMCSSRule)
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMCSSMediaRule)

dom/base/nsDOMClassInfoClasses.h

@@ -9,7 +9,6 @@ DOMCI_CLASS(DOMConstructor)
 
 // CSS classes
 DOMCI_CLASS(CSSStyleRule)
-DOMCI_CLASS(CSSImportRule)
 DOMCI_CLASS(CSSMediaRule)
 
 // XUL classes

dom/base/nsWrapperCache.h

@@ -19,7 +19,6 @@ class TabChildGlobal;
 class ProcessGlobal;
 } // namespace dom
 namespace css {
-class ImportRule;
 class StyleRule;
 class MediaRule;
 class DocumentRule;
@@ -292,7 +291,6 @@ private:
   friend class SandboxPrivate;
   friend class nsInProcessTabChildGlobal;
   friend class nsWindowRoot;
-  friend class mozilla::css::ImportRule;
   friend class mozilla::css::StyleRule;
   friend class mozilla::css::MediaRule;
   friend class mozilla::css::DocumentRule;

dom/bindings/Bindings.conf

@@ -197,6 +197,10 @@ DOMInterfaces = {
     'nativeType': 'nsDOMCSSDeclaration'
 },
 
+'CSSImportRule': {
+    'nativeType': 'mozilla::css::ImportRule',
+},
+
 'CSSLexer': {
     'wrapperCache': False
 },

dom/webidl/CSSImportRule.webidl

@@ -0,0 +1,17 @@
+/* -*- 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
+ * https://drafts.csswg.org/cssom/#cssimportrule
+ */
+
+// https://drafts.csswg.org/cssom/#cssimportrule
+interface CSSImportRule : CSSRule {
+  readonly attribute DOMString href;
+  [SameObject, PutForwards=mediaText] readonly attribute MediaList media;
+  // Per spec, the .styleSheet is never null, but in our implementation it can
+  // be.  See <https://bugzilla.mozilla.org/show_bug.cgi?id=1326509>.
+  [SameObject] readonly attribute CSSStyleSheet? styleSheet;
+};

dom/webidl/moz.build

@@ -90,6 +90,7 @@ WEBIDL_FILES = [
     'CSPReport.webidl',
     'CSS.webidl',
     'CSSAnimation.webidl',
+    'CSSImportRule.webidl',
     'CSSLexer.webidl',
     'CSSNamespaceRule.webidl',
     'CSSPrimitiveValue.webidl',

js/xpconnect/tests/chrome/test_weakmaps.xul

@@ -214,28 +214,8 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=668855
 
   make_live_map();
 
-  let unpreservable_native_key = function () {
-    // We only allow natives that support wrapper preservation to be used as weak
-    // map keys.  We should be able to try to add unpreservable natives as keys without
-    // crashing (bug 711616), but we should throw an error (bug 761620).
-
-    let dummy_test_map = new WeakMap;
-
-    let rule_fail = false;
-    let got_rule = false;
-    try {
-      var rule = document.styleSheets[0].cssRules[0];
-      got_rule = true;
-      dummy_test_map.set(rule, 1);
-    } catch (e) {
-      rule_fail = true;
-    }
-    ok(got_rule, "Got the CSS rule");
-    ok(rule_fail, "Using a CSS rule as a weak map key should produce an exception because it can't be wrapper preserved.");
-
-  }
-
-  unpreservable_native_key();
+  // We're out of ideas for unpreservable natives, now that just about
+  // everything is on webidl, so just don't test those.
 
   /* set up for running precise GC/CC then checking the results */
 

layout/style/ImportRule.h

@@ -20,6 +20,7 @@ class nsString;
 namespace mozilla {
 
 class CSSStyleSheet;
+class StyleSheet;
 
 namespace css {
 
@@ -61,6 +62,9 @@ public:
   // WebIDL interface
   uint16_t Type() const override;
   void GetCssTextImpl(nsAString& aCssText) const override;
+  // The XPCOM GetHref is fine, since it never fails.
+  nsMediaList* Media() const { return mMedia; }
+  StyleSheet* GetStyleSheet() const;
 
 private:
   nsString  mURLSpec;

layout/style/nsCSSRules.cpp

@@ -34,6 +34,7 @@
 #include "nsDOMClassInfoID.h"
 #include "mozilla/dom/CSSStyleDeclarationBinding.h"
 #include "mozilla/dom/CSSNamespaceRuleBinding.h"
+#include "mozilla/dom/CSSImportRuleBinding.h"
 #include "StyleRule.h"
 #include "nsFont.h"
 #include "nsIURI.h"
@@ -242,7 +243,7 @@ ImportRule::ImportRule(nsMediaList* aMedia, const nsString& aURLSpec,
   , mURLSpec(aURLSpec)
   , mMedia(aMedia)
 {
-  SetIsNotDOMBinding();
+  MOZ_ASSERT(aMedia);
   // XXXbz This is really silly.... the mMedia here will be replaced
   // with itself if we manage to load a sheet.  Which should really
   // never fail nowadays, in sane cases.
@@ -252,7 +253,6 @@ ImportRule::ImportRule(const ImportRule& aCopy)
   : Rule(aCopy),
     mURLSpec(aCopy.mURLSpec)
 {
-  SetIsNotDOMBinding();
   // Whether or not an @import rule has a null sheet is a permanent
   // property of that @import rule, since it is null only if the target
   // sheet failed security checks.
@@ -284,7 +284,6 @@ ImportRule::IsCCLeaf() const
 // QueryInterface implementation for ImportRule
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(ImportRule)
   NS_INTERFACE_MAP_ENTRY(nsIDOMCSSImportRule)
-  NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(CSSImportRule)
 NS_INTERFACE_MAP_END_INHERITING(Rule)
 
 NS_IMPL_CYCLE_COLLECTION_CLASS(ImportRule)
@@ -373,6 +372,12 @@ ImportRule::GetCssTextImpl(nsAString& aCssText) const
   aCssText.Append(';');
 }
 
+StyleSheet*
+ImportRule::GetStyleSheet() const
+{
+  return mChildSheet;
+}
+
 NS_IMETHODIMP
 ImportRule::GetHref(nsAString & aHref)
 {
@@ -385,7 +390,7 @@ ImportRule::GetMedia(nsIDOMMediaList * *aMedia)
 {
   NS_ENSURE_ARG_POINTER(aMedia);
 
-  NS_IF_ADDREF(*aMedia = mMedia);
+  NS_ADDREF(*aMedia = mMedia);
   return NS_OK;
 }
 
@@ -416,8 +421,7 @@ ImportRule::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
 ImportRule::WrapObject(JSContext* aCx,
                        JS::Handle<JSObject*> aGivenProto)
 {
-  NS_NOTREACHED("We called SetIsNotDOMBinding() in our constructor");
-  return nullptr;
+  return CSSImportRuleBinding::Wrap(aCx, this, aGivenProto);
 }
 
 GroupRule::GroupRule(uint32_t aLineNumber, uint32_t aColumnNumber)