Slightly more elegant results of queries

lib/cartodb/backends/layer-stats/mapnik-layer-stats.js

@@ -235,7 +235,10 @@ function (layer, dbConnection, callback) {
     // to define the queries of the second phase
     queries.phase(() => firstPhaseQueries(queries, context));
     queries.phase(() => secondPhaseQueries(queries, context));
-    queries.run(results => callback(null, results)).catch(error => callback(error));
+    queries.run()
+        .then(results => callback(null, results))
+        .catch(error => callback(error));
+
 };
 
 module.exports = MapnikLayerStats;

lib/cartodb/utils/phased-execution.js

@@ -65,7 +65,7 @@
  *         }));
  *     });
  *     // Execute all tasks
- *     p.run((results) => {
+ *     p.run().then((results) => {
  *         console.log("RESULTS:", results);
  *     }).catch((err) => {
  *         console.log("ERROR:", error);
@@ -82,14 +82,13 @@ module.exports = class PhasedExecution {
     task(promise) {
         this.tasks.push(promise);
     }
-    run(callback) {
+    run() {
         this.tasks = [];
         let phase = this.phases.shift();
         if (phase) {
             phase(this);
-            return Promise.all(this.tasks)
-                .then(() => this.run())
-                .then(() => { if (callback) { callback(this.results); } });
+            return Promise.all(this.tasks).then(() => this.run());
         }
+        return this.results;
     }
 };