Emulate click events only on mouse "action"

`click` events are fired only if the mouse action button is pressed. This prevents `click` events from being fired when the middle mouse button is used.

Also, without this commit, in Chrome with emulated touch events enabled, double-clicking the map doesn't zoom the map. This is because `ol.BrowserFeature.HAS_TOUCH` is `false` in that environment. The commit fixes it by testing `isMouseActionButton` on mouse devices only.

src/ol/interaction/doubleclickzoominteraction.js

@@ -46,8 +46,7 @@ ol.interaction.DoubleClickZoom.prototype.handleMapBrowserEvent =
     function(mapBrowserEvent) {
   var stopEvent = false;
   var browserEvent = mapBrowserEvent.browserEvent;
-  if (mapBrowserEvent.type == ol.MapBrowserEvent.EventType.DBLCLICK &&
+  if (mapBrowserEvent.type == ol.MapBrowserEvent.EventType.DBLCLICK) {
-      mapBrowserEvent.isMouseActionButton()) {
     var map = mapBrowserEvent.map;
     var anchor = mapBrowserEvent.getCoordinate();
     var delta = browserEvent.shiftKey ? -this.delta_ : this.delta_;

src/ol/mapbrowserevent.js

@@ -8,7 +8,6 @@ goog.require('goog.events');
 goog.require('goog.events.BrowserEvent');
 goog.require('goog.events.EventTarget');
 goog.require('goog.events.EventType');
-goog.require('ol.BrowserFeature');
 goog.require('ol.Coordinate');
 goog.require('ol.FrameState');
 goog.require('ol.MapEvent');
@@ -76,16 +75,6 @@ ol.MapBrowserEvent.prototype.getPixel = function() {
 };
 
 
-/**
- * @return {boolean} Do we have a left click?
- */
-ol.MapBrowserEvent.prototype.isMouseActionButton = function() {
-  // always assume a left-click on touch devices
-  return ol.BrowserFeature.HAS_TOUCH ||
-      this.browserEvent.isMouseActionButton();
-};
-
-
 /**
  * Prevents the default browser action.
  * @see https://developer.mozilla.org/en-US/docs/Web/API/event.preventDefault
@@ -226,7 +215,7 @@ ol.MapBrowserEventHandler.prototype.handleMouseUp_ = function(browserEvent) {
           ol.MapBrowserEvent.EventType.DRAGEND, this.map_, browserEvent);
       this.dispatchEvent(newEvent);
       this.down_ = null;
-    } else {
+    } else if (browserEvent.isMouseActionButton()) {
       this.emulateClick_(browserEvent);
     }
   }