Revert 78366 - Revert 78101 - Merge r76728, crbug 68263

WebCore/css/CSSStyleSheet.cpp

Index: WebCore/css/CSSStyleSheet.cpp
===================================================================
--- WebCore/css/CSSStyleSheet.cpp	(revision 78377)
+++ WebCore/css/CSSStyleSheet.cpp	(working copy)
@@ -53,7 +53,6 @@
 
 CSSStyleSheet::CSSStyleSheet(CSSStyleSheet* parentSheet, const String& href, const KURL& baseURL, const String& charset)
     : StyleSheet(parentSheet, href, baseURL)
-    , m_document(parentSheet ? parentSheet->document() : 0)
     , m_charset(charset)
     , m_loadCompleted(false)
     , m_strictParsing(!parentSheet || parentSheet->useStrictParsing())
@@ -64,7 +63,6 @@
 
 CSSStyleSheet::CSSStyleSheet(Node* parentNode, const String& href, const KURL& baseURL, const String& charset)
     : StyleSheet(parentNode, href, baseURL)
-    , m_document(parentNode->document())
     , m_charset(charset)
     , m_loadCompleted(false)
     , m_strictParsing(false)
@@ -82,7 +80,6 @@
     , m_hasSyntacticallyValidCSSHeader(true)
 {
     CSSStyleSheet* parentSheet = ownerRule ? ownerRule->parentStyleSheet() : 0;
-    m_document = parentSheet ? parentSheet->document() : 0;
     m_isUserStyleSheet = parentSheet ? parentSheet->isUserStyleSheet() : false;
 }
 
@@ -233,6 +230,24 @@
     m_loadCompleted = ownerNode() ? ownerNode()->sheetLoaded() : true;
 }
 
+Document* CSSStyleSheet::document()
+{
+    StyleBase* styleObject = this;
+    while (styleObject) {
+        if (styleObject->isCSSStyleSheet()) {
+            Node* ownerNode = static_cast<CSSStyleSheet*>(styleObject)->ownerNode();
+            if (ownerNode)
+                return ownerNode->document();
+        }
+        if (styleObject->isRule())
+            styleObject = static_cast<CSSRule*>(styleObject)->parentStyleSheet();
+        else
+            styleObject = styleObject->parent();
+    }
+
+    return 0;
+}
+
 void CSSStyleSheet::styleSheetChanged()
 {
     StyleBase* root = this;