Implement contextmenu attribute with basic support of <menu>

Source/core/page/ContextMenuController.h

Index: Source/core/page/ContextMenuController.h
diff --git a/Source/core/page/ContextMenuController.h b/Source/core/page/ContextMenuController.h
index 6ba0a9217f9accfec9f2602d31ee260bfeb828f9..6c766a2dc8e2aa1520ac1383e537791bcd037ff2 100644
--- a/Source/core/page/ContextMenuController.h
+++ b/Source/core/page/ContextMenuController.h
@@ -40,6 +40,8 @@ namespace blink {
     class ContextMenuProvider;
     class Document;
     class Event;
+    class HTMLElement;
+    class HTMLMenuElement;
     class LocalFrame;
     class Page;
 
@@ -57,6 +59,8 @@ namespace blink {
         void handleContextMenuEvent(Event*);
         void showContextMenu(Event*, PassRefPtr<ContextMenuProvider>);
         void showContextMenuAtPoint(LocalFrame*, float x, float y, PassRefPtr<ContextMenuProvider>);
+        HTMLElement* menuItemAt(unsigned menuId);
+        HTMLElement* subjectElement() { return m_subject.get(); }
 
         void contextMenuItemSelected(const ContextMenuItem*);
 
@@ -67,11 +71,14 @@ namespace blink {
 
         PassOwnPtr<ContextMenu> createContextMenu(Event*);
         PassOwnPtr<ContextMenu> createContextMenu(LocalFrame*, const LayoutPoint&);
+        void populateContextMenuItems(const HTMLMenuElement&, ContextMenu&);
         void showContextMenu(Event*);
 
         ContextMenuClient* m_client;
         OwnPtr<ContextMenu> m_contextMenu;
         RefPtr<ContextMenuProvider> m_menuProvider;
+        RefPtr<HTMLElement> m_subject;

[tkent, 2014/07/31 06:07:56]

Someone needs to clear m_subject and m_menuItems after closing a context menu.

[pals, 2014/08/01 10:03:08]

Done. Clearing at CustomContextMenuProvider::contextMenuCleared().

+        Vector<HTMLElement*> m_menuItems;
         HitTestResult m_hitTestResult;
     };