Support for CSSOM CSSNamespaceRule interface

Source/core/css/StyleSheetContents.cpp

Index: Source/core/css/StyleSheetContents.cpp
diff --git a/Source/core/css/StyleSheetContents.cpp b/Source/core/css/StyleSheetContents.cpp
index 8769973ac24db5e64a08a10153db03957ce0627b..d6475d62fe5a6f768642a53bc894bda2f2952ef0 100644
--- a/Source/core/css/StyleSheetContents.cpp
+++ b/Source/core/css/StyleSheetContents.cpp
@@ -156,10 +156,12 @@ void StyleSheetContents::parserAppendRule(PassRefPtrWillBeRawPtr<StyleRuleBase>
     }
 
     if (rule->isNamespaceRule()) {
-        // Parser enforces that @namespace rules come before anything else
+        // Parser enforces that @namespace rules come before all rules except for import
+        // or namespace rules

[Timothy Loh, 2015/09/02 04:45:14]

namespace -> charset?

[ramya.v, 2015/09/02 09:20:54]

Done.

         ASSERT(m_childRules.isEmpty());
         StyleRuleNamespace& namespaceRule = toStyleRuleNamespace(*rule);
         parserAddNamespace(namespaceRule.prefix(), namespaceRule.uri());
+        m_namespaceRules.append(&namespaceRule);
         return;
     }
 
@@ -184,12 +186,18 @@ StyleRuleBase* StyleSheetContents::ruleAt(unsigned index) const
         return m_importRules[index].get();
 
     index -= m_importRules.size();
+
+    if (index < m_namespaceRules.size())
+        return m_namespaceRules[index].get();
+
+    index -= m_namespaceRules.size();
+
     return m_childRules[index].get();
 }
 
 unsigned StyleSheetContents::ruleCount() const
 {
-    return m_importRules.size() + m_childRules.size();
+    return m_importRules.size() + m_namespaceRules.size() + m_childRules.size();
 }
 
 void StyleSheetContents::clearRules()
@@ -199,6 +207,7 @@ void StyleSheetContents::clearRules()
         m_importRules[i]->clearParentStyleSheet();
     }
     m_importRules.clear();
+    m_namespaceRules.clear();
     m_childRules.clear();
 }
 
@@ -231,6 +240,21 @@ bool StyleSheetContents::wrapperInsertRule(PassRefPtrWillBeRawPtr<StyleRuleBase>
 
     index -= m_importRules.size();
 
+    if (index < m_namespaceRules.size() || (index == m_namespaceRules.size() && rule->isNamespaceRule())) {
+        // Inserting non-namespace rules other than import rule before @namespace is not allowed.
+        if (!rule->isNamespaceRule())
+            return false;
+
+        StyleRuleNamespace* namespaceRule = toStyleRuleNamespace(rule.get());
+        m_namespaceRules.insert(index, namespaceRule);

[Timothy Loh, 2015/09/02 04:45:14]

..don't we need to also update m_namespaces? Currently (during stylesheet
parsing) we'll get into parserAddNamespace, although that currently assumes
we're only adding to the end.

[ramya.v, 2015/09/02 09:20:54]

Done.

+        return true;
+    }
+
+    if (rule->isNamespaceRule())
+        return false;
+
+    index -= m_namespaceRules.size();
+
     if (rule->isFontFaceRule())
         setHasFontFaceRule(true);
     m_childRules.insert(index, rule);
@@ -251,6 +275,12 @@ void StyleSheetContents::wrapperDeleteRule(unsigned index)
     }
     index -= m_importRules.size();
 
+    if (index < m_namespaceRules.size()) {

[Timothy Loh, 2015/09/02 04:45:14]

From the spec:
If old rule is an @namespace at-rule, and list contains anything other than
@import at-rules, and @namespace at-rules, throw an InvalidStateError exception.

[ramya.v, 2015/09/02 09:20:54]

Done.

+        m_namespaceRules.remove(index);
+        return;
+    }
+    index -= m_namespaceRules.size();
+
     if (m_childRules[index]->isFontFaceRule())
         notifyRemoveFontFaceRule(toStyleRuleFontFace(m_childRules[index].get()));
     m_childRules.remove(index);
@@ -624,6 +654,7 @@ DEFINE_TRACE(StyleSheetContents)
 #if ENABLE(OILPAN)
     visitor->trace(m_ownerRule);
     visitor->trace(m_importRules);
+    visitor->trace(m_namespaceRules);
     visitor->trace(m_childRules);
     visitor->trace(m_loadingClients);
     visitor->trace(m_completedClients);