[Plugins] Bring over timeline, clock plugins

WTD-1239

platform/features/clock/src/actions/AbstractStartTimerAction.js

@@ -0,0 +1,41 @@
+/*global define*/
+
+define(
+    [],
+    function () {
+        "use strict";
+
+        /**
+         * Implements the "Start" and "Restart" action for timers.
+         *
+         * Sets the reference timestamp in a timer to the current
+         * time, such that it begins counting up.
+         *
+         * Both "Start" and "Restart" share this implementation, but
+         * control their visibility with different `appliesTo` behavior.
+         *
+         * @implements Action
+         */
+        function AbstractStartTimerAction(now, context) {
+            var domainObject = context.domainObject;
+
+            function doPersist() {
+                var persistence = domainObject.getCapability('persistence');
+                return persistence && persistence.persist();
+            }
+
+            function setTimestamp(model) {
+                model.timestamp = now();
+            }
+
+            return {
+                perform: function () {
+                    return domainObject.useCapability('mutation', setTimestamp)
+                        .then(doPersist);
+                }
+            };
+        }
+
+        return AbstractStartTimerAction;
+    }
+);