Revert "Allow XHR timeout attribute to be overridden after send(), per spec"

Source/core/loader/ThreadableLoader.h

Index: Source/core/loader/ThreadableLoader.h
diff --git a/Source/core/loader/ThreadableLoader.h b/Source/core/loader/ThreadableLoader.h
index 1f851c489d13e6e05d4428640f61491d0b0bad30..d3375043ae81baae0cb8e3cf05b80c2f1b10f43a 100644
--- a/Source/core/loader/ThreadableLoader.h
+++ b/Source/core/loader/ThreadableLoader.h
@@ -90,13 +90,6 @@ namespace WebCore {
         static void loadResourceSynchronously(ExecutionContext&, const ResourceRequest&, ThreadableLoaderClient&, const ThreadableLoaderOptions&, const ResourceLoaderOptions&);
         static PassRefPtr<ThreadableLoader> create(ExecutionContext&, ThreadableLoaderClient*, const ResourceRequest&, const ThreadableLoaderOptions&, const ResourceLoaderOptions&);
 
-        // A ThreadableLoader may have a timeout specified. It is possible, in some cases, for
-        // the timeout to be overridden after the request is sent (for example, XMLHttpRequests
-        // may override their timeout setting after sending).
-        //
-        // Set a new timeout relative to the time the request started, in milliseconds.
-        virtual void overrideTimeout(unsigned long timeoutMilliseconds) = 0;
-
         virtual void cancel() = 0;
 
         virtual ~ThreadableLoader() { }