Move the Widget hierarchy to the Oilpan heap.

Source/web/PopupMenuTest.cpp

Index: Source/web/PopupMenuTest.cpp
diff --git a/Source/web/PopupMenuTest.cpp b/Source/web/PopupMenuTest.cpp
index 3b82ddfb49eada90c3bc81598e4fed69192c3126..166c25c8fb12f4b11b9717a5f075851f20b5c0ea 100644
--- a/Source/web/PopupMenuTest.cpp
+++ b/Source/web/PopupMenuTest.cpp
@@ -126,7 +126,7 @@ public:
     virtual FontSelector* fontSelector() const { return 0; }
     virtual HostWindow* hostWindow() const { return 0; }
 
-    virtual PassRefPtr<Scrollbar> createScrollbar(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize) { return nullptr; }
+    virtual PassRefPtrWillBeRawPtr<Scrollbar> createScrollbar(ScrollableArea*, ScrollbarOrientation, ScrollbarControlSize) { return nullptr; }
 
     void setDisabledIndex(unsigned index) { m_disabledIndexSet.insert(index); }
     void setFocusedNode(Node* node) { m_node = node; }
@@ -195,6 +195,7 @@ protected:
 
     virtual void TearDown()
     {
+        m_popupMenu->disconnectClient();
         Platform::current()->unitTestSupport()->unregisterAllMockedURLs();
     }