Implement contextmenu attribute with basic support of <menu>

Source/core/html/HTMLElement.cpp

Index: Source/core/html/HTMLElement.cpp
diff --git a/Source/core/html/HTMLElement.cpp b/Source/core/html/HTMLElement.cpp
index c7e6eec81e8fdc6f9b10e2aff060bc58ae8fedb9..491e4145d135fabfbdd3770c07523b5cbcc6e159 100644
--- a/Source/core/html/HTMLElement.cpp
+++ b/Source/core/html/HTMLElement.cpp
@@ -45,6 +45,7 @@
 #include "core/html/HTMLBRElement.h"
 #include "core/html/HTMLFormElement.h"
 #include "core/html/HTMLInputElement.h"
+#include "core/html/HTMLMenuElement.h"
 #include "core/html/HTMLTemplateElement.h"
 #include "core/html/HTMLTextFormControlElement.h"
 #include "core/html/parser/HTMLParserIdioms.h"
@@ -903,6 +904,17 @@ bool HTMLElement::isInteractiveContent() const
     return false;
 }
 
+HTMLMenuElement* HTMLElement::menuElement() const
+{
+    Element* element = treeScope().getElementById(fastGetAttribute(contextmenuAttr));
+    if (!element)
+        return 0;
+    if (!isHTMLMenuElement(*element))

[esprehn, 2014/06/06 22:30:42]

You can combine all these checks into:

return isHTMLMenuElement(element) ? element : 0;

you don't even need to null check it then.

[pals, 2014/06/10 10:42:39]

Done.

+        return 0;
+
+    return toHTMLMenuElement(element);
+}
+
 void HTMLElement::defaultEventHandler(Event* event)
 {
     if (event->type() == EventTypeNames::keypress && event->isKeyboardEvent()) {