Apply listeners in constructor rather than ready

Fixes #4394. This change allows elements to have "first crack" at their own events (via the `listeners` object) before handlers registered via `on-*` see events. This is both more expected and fixes an inconsistency with 1.x.

lib/legacy/legacy-element-mixin.html

@@ -81,6 +81,11 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
         /** @type {Object<string, Function>} */
         this._debouncers;
         this.created();
+        // Ensure listeners are applied immediately so that they are
+        // added before declarative event listeners. This allows an element to
+        // decorate itself via an event prior to any declarative listeners
+        // seeing the event. Note, this ensures compatibility with 1.x ordering.
+        this._applyListeners();
       }
 
       /**
@@ -180,7 +185,6 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
        */
       ready() {
         this._ensureAttributes();
-        this._applyListeners();
         super.ready();
       }
 

lib/utils/gestures.html

@@ -579,7 +579,13 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
      */
     setTouchAction: function(node, value) {
       if (HAS_NATIVE_TA) {
-        node.style.touchAction = value;
+        // NOTE: add touchAction async so that events can be added in
+        // custom element constructors. Otherwise we run afoult of custom
+        // elements restriction against settings attributes (style) in the
+        // constructor.
+        Polymer.Async.microTask.run(() => {
+          node.style.touchAction = value;
+        });
       }
       node[TOUCH_ACTION] = value;
     },