Initialize GC mixin bases only when leftmost vtable has been initialized.

Source/core/svg/SVGTests.cpp

Index: Source/core/svg/SVGTests.cpp
diff --git a/Source/core/svg/SVGTests.cpp b/Source/core/svg/SVGTests.cpp
index 75281f1b92b135894d5800bbd5b109094ac491be..91ed88f437bbac8f03a271d00e38f8c0b4d11dec 100644
--- a/Source/core/svg/SVGTests.cpp
+++ b/Source/core/svg/SVGTests.cpp
@@ -30,13 +30,21 @@
 
 namespace blink {
 
-SVGTests::SVGTests(SVGElement* contextElement)
-    : m_requiredFeatures(SVGStaticStringList::create(contextElement, SVGNames::requiredFeaturesAttr))
-    , m_requiredExtensions(SVGStaticStringList::create(contextElement, SVGNames::requiredExtensionsAttr))
-    , m_systemLanguage(SVGStaticStringList::create(contextElement, SVGNames::systemLanguageAttr))
+SVGTests::SVGTests()
 {
+}
+
+void SVGTests::initialize(SVGElement* contextElement)
+{
+    ASSERT(!m_requiredFeatures.get());
+    ASSERT(!m_requiredExtensions.get());
+    ASSERT(!m_systemLanguage.get());

[haraken, 2015/01/20 15:40:32]

.get() won't be needed.

[sof, 2015/01/20 19:02:50]

Done, dropped them from the asserts here.

     ASSERT(contextElement);
 
+    m_requiredFeatures = SVGStaticStringList::create(contextElement, SVGNames::requiredFeaturesAttr);
+    m_requiredExtensions = SVGStaticStringList::create(contextElement, SVGNames::requiredExtensionsAttr);
+    m_systemLanguage = SVGStaticStringList::create(contextElement, SVGNames::systemLanguageAttr);
+
     contextElement->addToPropertyMap(m_requiredFeatures);
     contextElement->addToPropertyMap(m_requiredExtensions);
     contextElement->addToPropertyMap(m_systemLanguage);