Simpler return value from HashTable::add()/HashMap::add() and others

Source/core/rendering/svg/RenderSVGResourceGradient.cpp

Index: Source/core/rendering/svg/RenderSVGResourceGradient.cpp
diff --git a/Source/core/rendering/svg/RenderSVGResourceGradient.cpp b/Source/core/rendering/svg/RenderSVGResourceGradient.cpp
index 4e432a5608219b0991e1c29341f27f911decf523..b26cdffe131344e4aed3642d4e66179d71e92c80 100644
--- a/Source/core/rendering/svg/RenderSVGResourceGradient.cpp
+++ b/Source/core/rendering/svg/RenderSVGResourceGradient.cpp
@@ -81,7 +81,7 @@ bool RenderSVGResourceGradient::applyResource(RenderObject* object, RenderStyle*
     if (gradientUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX && objectBoundingBox.isEmpty())
         return false;
 
-    OwnPtr<GradientData>& gradientData = m_gradientMap.add(object, nullptr).iterator->value;
+    OwnPtr<GradientData>& gradientData = m_gradientMap.add(object, nullptr).storedValue->value;
     if (!gradientData)
         gradientData = adoptPtr(new GradientData);