fix($browser): .url() should return self in setter mode

Author: thorn0

src/ng/browser.js

@@ -170,7 +170,7 @@ function Browser(window, document, $log, $sniffer) {
       // IE<10 from getting into redirect loop when in LocationHashbangInHtml5Url mode.
       // See https://github.com/angular/angular.js/commit/ffb2701
       if (lastBrowserUrl === url && (!$sniffer.history || sameState)) {
-        return;
+        return self;
       }
       var sameBase = lastBrowserUrl && stripHash(lastBrowserUrl) === stripHash(url);
       lastBrowserUrl = url;