Use DEFINE_NODE_TYPE_CASTS instead of using manual toHTMLFooElement()

Source/core/html/HTMLImageElement.h

Index: Source/core/html/HTMLImageElement.h
diff --git a/Source/core/html/HTMLImageElement.h b/Source/core/html/HTMLImageElement.h
index 4566051b24b05e33c2e219dfaf1b603a912794ad..4b5d248dfee87a2b98aeaeba1cd7c61160672cc4 100644
--- a/Source/core/html/HTMLImageElement.h
+++ b/Source/core/html/HTMLImageElement.h
@@ -118,17 +118,7 @@ private:
     float m_imageDevicePixelRatio;
 };
 
-inline HTMLImageElement* toHTMLImageElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(HTMLNames::imgTag));
-    return static_cast<HTMLImageElement*>(node);
-}
-
-inline const HTMLImageElement* toHTMLImageElement(const Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(HTMLNames::imgTag));
-    return static_cast<const HTMLImageElement*>(node);
-}
+DEFINE_NODE_TYPE_CASTS(HTMLImageElement, hasTagName(HTMLNames::imgTag));
 
 } //namespace