Implement contextmenu attribute with basic support of <menu>

Source/core/html/CustomContextMenuProvider.cpp

Index: Source/core/html/CustomContextMenuProvider.cpp
diff --git a/Source/core/html/CustomContextMenuProvider.cpp b/Source/core/html/CustomContextMenuProvider.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..44e0b415c29c81049e390024fcfee0463f8aed92
--- /dev/null
+++ b/Source/core/html/CustomContextMenuProvider.cpp
@@ -0,0 +1,38 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/html/CustomContextMenuProvider.h"
+
+#include "core/dom/Document.h"
+#include "core/events/EventDispatcher.h"
+#include "core/events/MouseEvent.h"
+#include "core/html/HTMLMenuElement.h"
+#include "platform/ContextMenu.h"
+
+namespace WebCore {

[Inactive, 2014/07/23 14:19:07]

blink

[pals, 2014/07/24 10:49:25]

Done.

+
+CustomContextMenuProvider::~CustomContextMenuProvider()
+{
+}
+
+void CustomContextMenuProvider::populateContextMenu(ContextMenu* menu)
+{
+    for (size_t i = 0; i < m_items.size(); ++i)
+        menu->appendItem(m_items[i]);
+}
+
+void CustomContextMenuProvider::contextMenuItemSelected(const ContextMenuItem* item)
+{
+    if (!m_menu)

[Inactive, 2014/07/23 14:19:07]

Just to confirm, can this happen or not? If it shouldn't happen, then this
should be an assertion. Otherwise, it is fine to have an if check.

[pals, 2014/07/24 10:49:26]

This can happen if user has been shown context menu and js has removed the menu
from dom before selecting any item.

+        return;
+
+    if (HTMLElement* element = m_menu->menuItemAt(item->action())) {

[Inactive, 2014/07/23 14:19:07]

HTMLMenuItemElement*

[pals, 2014/07/24 10:49:26]

Done.

+        RefPtrWillBeRawPtr<SimulatedMouseEvent> click = SimulatedMouseEvent::create(EventTypeNames::click, m_menu->document().domWindow(), Event::create());
+        click->setRelatedTarget(m_menu->subjectElement());
+        EventDispatcher::dispatchEvent(element, EventDispatchMediator::create(click.release()));
+    }
+}
+
+} // namespace

[Inactive, 2014/07/23 14:19:07]

blink

[pals, 2014/07/24 10:49:26]

Done.