Oilpan: have xml/ objects on the heap by default.

Source/core/xml/XSLStyleSheetLibxslt.cpp

Index: Source/core/xml/XSLStyleSheetLibxslt.cpp
diff --git a/Source/core/xml/XSLStyleSheetLibxslt.cpp b/Source/core/xml/XSLStyleSheetLibxslt.cpp
index c414a82556a022d8d9a9de5307b972621e71ad1a..75c6483404ee9c2547d3eaea5efc739cc277522f 100644
--- a/Source/core/xml/XSLStyleSheetLibxslt.cpp
+++ b/Source/core/xml/XSLStyleSheetLibxslt.cpp
@@ -228,10 +228,9 @@ void XSLStyleSheet::loadChildSheets()
 
 void XSLStyleSheet::loadChildSheet(const String& href)
 {
-    OwnPtrWillBeRawPtr<XSLImportRule> childRule = XSLImportRule::create(this, href);
-    XSLImportRule* c = childRule.get();
-    m_children.append(childRule.release());
-    c->loadSheet();
+    XSLImportRule* childRule = XSLImportRule::create(this, href);
+    m_children.append(childRule);
+    childRule->loadSheet();
 }
 
 xsltStylesheetPtr XSLStyleSheet::compileStyleSheet()