Replace RenderArena with PartitionAlloc.

Source/core/html/HTMLPlugInImageElement.cpp

Index: Source/core/html/HTMLPlugInImageElement.cpp
diff --git a/Source/core/html/HTMLPlugInImageElement.cpp b/Source/core/html/HTMLPlugInImageElement.cpp
index 622dbc28b1f6355a22c7fa81bab7f41a03923d35..9701d4907bad130db3976ecf479f0739cd510026 100644
--- a/Source/core/html/HTMLPlugInImageElement.cpp
+++ b/Source/core/html/HTMLPlugInImageElement.cpp
@@ -135,7 +135,7 @@ bool HTMLPlugInImageElement::wouldLoadAsNetscapePlugin(const String& url, const
     return false;
 }
 
-RenderObject* HTMLPlugInImageElement::createRenderer(RenderArena* arena, RenderStyle* style)
+RenderObject* HTMLPlugInImageElement::createRenderer(RenderStyle* style)
 {
     // Fallback content breaks the DOM->Renderer class relationship of this
     // class and all superclasses because createObject won't necessarily
@@ -144,12 +144,12 @@ RenderObject* HTMLPlugInImageElement::createRenderer(RenderArena* arena, RenderS
         return RenderObject::createObject(this, style);
 
     if (isImageType()) {
-        RenderImage* image = new (arena) RenderImage(this);
+        RenderImage* image = new RenderImage(this);
         image->setImageResource(RenderImageResource::create());
         return image;
     }
 
-    return new (arena) RenderEmbeddedObject(this);
+    return new RenderEmbeddedObject(this);
 }
 
 void HTMLPlugInImageElement::willRecalcStyle(StyleChange)