Oilpan: move context menu providers to the heap.

Source/core/page/CustomContextMenuProvider.cpp

Index: Source/core/page/CustomContextMenuProvider.cpp
diff --git a/Source/core/page/CustomContextMenuProvider.cpp b/Source/core/page/CustomContextMenuProvider.cpp
index 0bd522c24da53527778c98056972c89ee36f99b3..77795a8573ae69ac13d2127d1fd88a96cd3cfd9f 100644
--- a/Source/core/page/CustomContextMenuProvider.cpp
+++ b/Source/core/page/CustomContextMenuProvider.cpp
@@ -29,6 +29,14 @@ CustomContextMenuProvider::~CustomContextMenuProvider()
 {
 }
 
+void CustomContextMenuProvider::trace(Visitor* visitor)
+{
+    visitor->trace(m_menu);
+    visitor->trace(m_subjectElement);
+    visitor->trace(m_menuItems);
+    ContextMenuProvider::trace(visitor);
+}
+
 void CustomContextMenuProvider::populateContextMenu(ContextMenu* menu)
 {
     populateContextMenuItems(*m_menu, *menu);