Move the Widget hierarchy to the Oilpan heap.

Source/core/loader/EmptyClients.h

Index: Source/core/loader/EmptyClients.h
diff --git a/Source/core/loader/EmptyClients.h b/Source/core/loader/EmptyClients.h
index 6b72c5d9448178610be40fd4ef69cc3493378793..f9f3cbe248e03acd7abb1475b7a1697f6442221e 100644
--- a/Source/core/loader/EmptyClients.h
+++ b/Source/core/loader/EmptyClients.h
@@ -228,9 +228,9 @@ public:
     virtual void didDispatchPingLoader(const KURL&) OVERRIDE { }
     virtual void selectorMatchChanged(const Vector<String>&, const Vector<String>&) OVERRIDE { }
     virtual PassRefPtrWillBeRawPtr<LocalFrame> createFrame(const KURL&, const AtomicString&, const Referrer&, HTMLFrameOwnerElement*) OVERRIDE;
-    virtual PassRefPtr<Widget> createPlugin(HTMLPlugInElement*, const KURL&, const Vector<String>&, const Vector<String>&, const String&, bool, DetachedPluginPolicy) OVERRIDE;
+    virtual PassRefPtrWillBeRawPtr<Widget> createPlugin(HTMLPlugInElement*, const KURL&, const Vector<String>&, const Vector<String>&, const String&, bool, DetachedPluginPolicy) OVERRIDE;
     virtual bool canCreatePluginWithoutRenderer(const String& mimeType) const OVERRIDE { return false; }
-    virtual PassRefPtr<Widget> createJavaAppletWidget(HTMLAppletElement*, const KURL&, const Vector<String>&, const Vector<String>&) OVERRIDE;
+    virtual PassRefPtrWillBeRawPtr<Widget> createJavaAppletWidget(HTMLAppletElement*, const KURL&, const Vector<String>&, const Vector<String>&) OVERRIDE;
 
     virtual ObjectContentType objectContentType(const KURL&, const String&, bool) OVERRIDE { return ObjectContentType(); }