Oilpan: revert SVG GC mixin constructor workaround.

Source/core/svg/animation/SVGSMILElement.cpp

Index: Source/core/svg/animation/SVGSMILElement.cpp
diff --git a/Source/core/svg/animation/SVGSMILElement.cpp b/Source/core/svg/animation/SVGSMILElement.cpp
index d9f97bfad30c824bfb04a6b9fbd955333f26d9bc..aa2d3ead55f203a0ca7e15b8e5be34d52aa9379e 100644
--- a/Source/core/svg/animation/SVGSMILElement.cpp
+++ b/Source/core/svg/animation/SVGSMILElement.cpp
@@ -171,6 +171,7 @@ SVGSMILElement::Condition::Condition(Type type, BeginOrEnd beginOrEnd, const Str
 
 SVGSMILElement::SVGSMILElement(const QualifiedName& tagName, Document& doc)
     : SVGElement(tagName, doc)
+    , SVGTests(this)
     , m_attributeName(anyQName())
     , m_targetElement(nullptr)
     , m_syncBaseConditionsConnected(false)
@@ -190,8 +191,6 @@ SVGSMILElement::SVGSMILElement(const QualifiedName& tagName, Document& doc)
     , m_cachedMin(invalidCachedTime)
     , m_cachedMax(invalidCachedTime)
 {
-    SVGTests::initialize(this);
-
     resolveFirstInterval();
 }