Have Node::document() return a reference instead of a pointer

Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp

Index: Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp
diff --git a/Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp b/Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp
index 73b8d6303a5a952481764c84dd5752d3d2d18c9e..58c198e7ebce1c77944646335b07d3479d55130b 100644
--- a/Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp
+++ b/Source/bindings/v8/custom/V8InjectedScriptHostCustom.cpp
@@ -273,9 +273,7 @@ void V8InjectedScriptHost::getEventListenersMethodCustom(const v8::FunctionCallb
     if (!node)
         return;
     // This can only happen for orphan DocumentType nodes.
-    Document* document = node->document();
-    if (!node->document())
-        return;
+    Document& document = node->document();
 
     InjectedScriptHost* host = V8InjectedScriptHost::toNative(args.Holder());
     Vector<EventListenerInfo> listenersArray;
@@ -283,7 +281,7 @@ void V8InjectedScriptHost::getEventListenersMethodCustom(const v8::FunctionCallb
 
     v8::Local<v8::Object> result = v8::Object::New();
     for (size_t i = 0; i < listenersArray.size(); ++i) {
-        v8::Handle<v8::Array> listeners = getJSListenerFunctions(document, listenersArray[i]);
+        v8::Handle<v8::Array> listeners = getJSListenerFunctions(&document, listenersArray[i]);
         if (!listeners->Length())
             continue;
         AtomicString eventType = listenersArray[i].eventType;