[Media Router WebUI] Remove unnecessary default property values.

chrome/test/data/webui/media_router/route_details_tests.js

Index: chrome/test/data/webui/media_router/route_details_tests.js
diff --git a/chrome/test/data/webui/media_router/route_details_tests.js b/chrome/test/data/webui/media_router/route_details_tests.js
index db00144d24707d190dec4bf602188d6fb918a681..2d8d0741f9dd6ba16169181b6ef33dccbfaac771 100644
--- a/chrome/test/data/webui/media_router/route_details_tests.js
+++ b/chrome/test/data/webui/media_router/route_details_tests.js
@@ -108,18 +108,18 @@ cr.define('route_details', function() {
         checkSpanText(loadTimeData.getString('stopCastingButtonText')
             .toUpperCase(), 'close-route-button');
         checkSpanText(
-            loadTimeData.getString('startCastingButtonText'),
+            loadTimeData.getString('startCastingButtonText').toUpperCase(),
             'start-casting-to-route-button');
         checkSpanText('', 'route-information');
       });
 
-      // Tests when |route| is null or set.
-      test('route is null or set', function() {
-        // |route| is null.
-        assertEquals(null, details.route);
+      // Tests when |route| is undefined or set.
+      test('route is undefined or set', function() {
+        // |route| is initially undefined.
+        assertEquals(undefined, details.route);
         checkDefaultViewIsShown();
 
-        // Set |route| to be non-null.
+        // Set |route|.
         details.route = fakeRouteOne;
         assertEquals(fakeRouteOne, details.route);
         checkSpanText(loadTimeData.getStringF('castingActivityStatus',