Implement computedRole and computedName (behind a flag)

Source/modules/accessibility/AXScrollbar.cpp

Index: Source/modules/accessibility/AXScrollbar.cpp
diff --git a/Source/modules/accessibility/AXScrollbar.cpp b/Source/modules/accessibility/AXScrollbar.cpp
index de5bae3d0f2ef3443a6a5a6227b902a2e309854c..3f9753700da2c203c5372beaf239b126d9201ed2 100644
--- a/Source/modules/accessibility/AXScrollbar.cpp
+++ b/Source/modules/accessibility/AXScrollbar.cpp
@@ -29,13 +29,15 @@
 #include "config.h"
 #include "modules/accessibility/AXScrollbar.h"
 
+#include "core/dom/AXObjectCache.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "platform/scroll/Scrollbar.h"
 
 namespace blink {
 
-AXScrollbar::AXScrollbar(Scrollbar* scrollbar)
-    : m_scrollbar(scrollbar)
+AXScrollbar::AXScrollbar(Scrollbar* scrollbar, AXObjectCache* axObjectCache)
+    : AXMockObject(axObjectCache)
+    , m_scrollbar(scrollbar)
 {
     ASSERT(scrollbar);
 }
@@ -46,9 +48,9 @@ void AXScrollbar::detachFromParent()
     AXMockObject::detachFromParent();
 }
 
-PassRefPtr<AXScrollbar> AXScrollbar::create(Scrollbar* scrollbar)
+PassRefPtr<AXScrollbar> AXScrollbar::create(Scrollbar* scrollbar, AXObjectCache* axObjectCache)
 {
-    return adoptRef(new AXScrollbar(scrollbar));
+    return adoptRef(new AXScrollbar(scrollbar, axObjectCache));
 }
 
 LayoutRect AXScrollbar::elementRect() const