Have Frame::script() return a reference

Source/web/FrameLoaderClientImpl.cpp

Index: Source/web/FrameLoaderClientImpl.cpp
diff --git a/Source/web/FrameLoaderClientImpl.cpp b/Source/web/FrameLoaderClientImpl.cpp
index d7b2ce97b1a9200f3435f19f3be911ae3da6e1c1..844fe3d6e1f8ce55e4c597cba01e575094c7a084 100644
--- a/Source/web/FrameLoaderClientImpl.cpp
+++ b/Source/web/FrameLoaderClientImpl.cpp
@@ -266,7 +266,7 @@ void FrameLoaderClientImpl::detachedFromParent()
     // will cause a crash.  If you remove/modify this, just ensure that you can
     // go to a page and then navigate to a new page without getting any asserts
     // or crashes.
-    m_webFrame->frame()->script()->clearForClose();
+    m_webFrame->frame()->script().clearForClose();
 
     // Alert the client that the frame is being detached. This is the last
     // chance we have to communicate with the client.