Fixing touch/mouse issues with TapEventPlugin

On ios device, browser simulates mouse events, but does that with
a delay, because of double tap gesture. The problem is that
TapEventPlugins listens to both types of events, so it fires twice

Everytime there is a touch event, we should ignore mouse events that
follow it.  This way, we still respond to both mouse and touch events,
just ignore the device generated ones.

src/browser/eventPlugins/TapEventPlugin.js

@@ -62,13 +62,15 @@ var dependencies = [
   topLevelTypes.topMouseUp
 ];
 
+var touchDependencies = [
+  topLevelTypes.topTouchStart,
+  topLevelTypes.topTouchCancel,
+  topLevelTypes.topTouchEnd,
+  topLevelTypes.topTouchMove
+];
+
 if (EventPluginUtils.useTouchEvents) {
-  dependencies.push(
-    topLevelTypes.topTouchCancel,
-    topLevelTypes.topTouchEnd,
-    topLevelTypes.topTouchStart,
-    topLevelTypes.topTouchMove
-  );
+  dependencies = dependencies.concat(touchDependencies);
 }
 
 var eventTypes = {
@@ -81,6 +83,10 @@ var eventTypes = {
   }
 };
 
+var usedTouch = false;
+var usedTouchTime = 0;
+var TOUCH_DELAY = 500;
+
 var TapEventPlugin = {
 
   tapMoveThreshold: tapMoveThreshold,
@@ -103,6 +109,17 @@ var TapEventPlugin = {
     if (!isStartish(topLevelType) && !isEndish(topLevelType)) {
       return null;
     }
+    // on ios, there is a delay after touch event and synthetic
+    // mouse events, so that user can perform double tap
+    // solution: ignore mouse events following touchevent within small timeframe
+    if (touchDependencies.indexOf(topLevelType) !== -1) {
+      usedTouch = true;
+      usedTouchTime = Date.now();
+    } else {
+      if (usedTouch && (Date.now() - usedTouchTime < TOUCH_DELAY)) {
+        return;
+      }
+    }
     var event = null;
     var distance = getDistance(startCoords, nativeEvent);
     if (isEndish(topLevelType) && distance < tapMoveThreshold) {