Replace RenderArena with PartitionAlloc.

Source/core/page/FrameView.cpp

Index: Source/core/page/FrameView.cpp
diff --git a/Source/core/page/FrameView.cpp b/Source/core/page/FrameView.cpp
index 754677d1ef77c0808d1896ea1dfa928fab64da34..87936f71e398af4f454f05004b1719d0009de362 100644
--- a/Source/core/page/FrameView.cpp
+++ b/Source/core/page/FrameView.cpp
@@ -63,7 +63,6 @@
 #include "core/platform/graphics/FontCache.h"
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/text/TextStream.h"
-#include "core/rendering/RenderArena.h"
 #include "core/rendering/RenderEmbeddedObject.h"
 #include "core/rendering/RenderFullScreen.h"
 #include "core/rendering/RenderIFrame.h"
@@ -2194,8 +2193,6 @@ bool FrameView::updateWidgets()
 
     Vector<RenderObject*> objects;
     objects.reserveInitialCapacity(size);
-    // Protect RendereArena from getting wiped out, when Document is detached during updateWidget().
-    RefPtr<RenderArena> protectedArena = m_frame->document()->renderArena();
 
     RenderObjectSet::const_iterator end = m_widgetUpdateSet->end();
     for (RenderObjectSet::const_iterator it = m_widgetUpdateSet->begin(); it != end; ++it) {
@@ -2217,7 +2214,7 @@ bool FrameView::updateWidgets()
         RenderObject* object = objects[i];
         if (object->isEmbeddedObject()) {
             RenderEmbeddedObject* embeddedObject = static_cast<RenderEmbeddedObject*>(object);
-            embeddedObject->deref(protectedArena.get());
+            embeddedObject->deref();
         }
     }