[Common UI] Fix Save/Cancel quirk

Fix a defect in the Save/Cancel buttons in Edit mode
that was causing the first click to be missed; this
was due to Angular's inability to detect when a
native promise (as opposed to one from ) had been
resolved.

Since the Editor capability is introduced indirectly
and is a few degrees of separation removed from
the declared extension layer (where we would be able
to get a reference to ), and all we need to do is
make something look Promise-like, a convenience
function to do this is added.

Part of ongoing transition of common user interface
elements, WTD-574.

platform/commonUI/edit/src/capabilities/EditorCapability.js

@@ -1,4 +1,4 @@
-/*global define,Promise*/
+/*global define*/
 
 define(
     [],
@@ -26,6 +26,20 @@ define(
             cache
         ) {
 
+            // Simulate Promise.resolve (or $q.when); the former
+            // causes a delayed reaction from Angular (since it
+            // does not trigger a digest) and the latter is not
+            // readily accessible, since we're a few classes
+            // removed from the layer which gets dependency
+            // injection.
+            function resolvePromise(value) {
+                return value && value.then ? value : {
+                    then: function (callback) {
+                        return resolvePromise(callback(value));
+                    }
+                };
+            }
+
             // Update the underlying, "real" domain object's model
             // with changes made to the copy used for editing.
             function doMutate() {
@@ -60,7 +74,7 @@ define(
                  *          persistence has completed.
                  */
                 save: function () {
-                    return Promise.resolve(doMutate())
+                    return resolvePromise(doMutate())
                         .then(doPersist)
                         .then(markClean)
                         .then(saveOthers);
@@ -73,7 +87,7 @@ define(
                  *          cancellation has completed.
                  */
                 cancel: function () {
-                    return Promise.resolve(undefined);
+                    return resolvePromise(undefined);
                 }
             };
         };