[Common UI] Spec for ViewSwitcherController

Fill in spec for the controller which maintains a set of
applicable and selected view options to populate the
view switcher. Part of Browse mode and, in turn, part
of the common user interface elements that are being
transitioned for WTD-574.

platform/commonUI/browse/src/ViewSwitcherController.js

@@ -31,8 +31,8 @@ define(
             }
 
             // Get list of views, read from capability
-            $scope.$watch("view", function () {
-                var options = $scope.view || [ {} ];
+            function updateOptions(views) {
+                var options = views || [];
 
                 $scope.switcher = {
                     options: options,
@@ -41,7 +41,11 @@ define(
                         ($scope.switcher || {}).selected
                     )
                 };
-            });
+            }
+
+            // Update view options when the in-scope results of using the
+            // view capability change.
+            $scope.$watch("view", updateOptions);
         }
 
         return ViewSwitcherController;