Remove Internals::createShadowRoot(element) and polyfill.js.

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 51e4016f94299e0ec9f5f65df16bc4fe8f99d005..03af170de32aa2ce12d4b9c6889af4c08611d648 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -632,15 +632,6 @@ ShadowRoot* Internals::ensureShadowRoot(Element* host, ExceptionCode& ec)
     return host->createShadowRoot(ec).get();
 }
 
-ShadowRoot* Internals::createShadowRoot(Element* host, ExceptionCode& ec)
-{
-    if (!host) {
-        ec = INVALID_ACCESS_ERR;
-        return 0;
-    }
-    return host->createShadowRoot(ec).get();
-}
-
 ShadowRoot* Internals::shadowRoot(Element* host, ExceptionCode& ec)
 {
     // FIXME: Internals::shadowRoot() in tests should be converted to youngestShadowRoot() or oldestShadowRoot().