refactor($location): remove obsolete workaround for Firefox bug

The bug was fixed in Firefox 48: https://bugzilla.mozilla.org/show_bug.cgi?id=684208,
and only affected the scenario runner

Author: Narretz

src/ng/location.js

@@ -938,8 +938,6 @@ function $LocationProvider() {
           // update location manually
           if ($location.absUrl() !== $browser.url()) {
             $rootScope.$apply();
-            // hack to work around FF6 bug 684208 when scenario runner clicks on links
-            $window.angular['ff-684208-preventDefault'] = true;
           }
         }
       }

src/ngMock/browserTrigger.js

@@ -147,30 +147,11 @@
 
     if (!evnt) return;
 
-    var originalPreventDefault = evnt.preventDefault,
-        appWindow = element.ownerDocument.defaultView,
-        fakeProcessDefault = true,
-        finalProcessDefault,
-        angular = appWindow.angular || {};
-
-    // igor: temporary fix for https://bugzilla.mozilla.org/show_bug.cgi?id=684208
-    angular['ff-684208-preventDefault'] = false;
-    evnt.preventDefault = function() {
-      fakeProcessDefault = false;
-      return originalPreventDefault.apply(evnt, arguments);
-    };
-
     if (!eventData.bubbles || supportsEventBubblingInDetachedTree() || isAttachedToDocument(element)) {
-      element.dispatchEvent(evnt);
+      return element.dispatchEvent(evnt);
     } else {
       triggerForPath(element, evnt);
     }
-
-    finalProcessDefault = !(angular['ff-684208-preventDefault'] || !fakeProcessDefault);
-
-    delete angular['ff-684208-preventDefault'];
-
-    return finalProcessDefault;
   };
 
   function supportsTouchEvents() {