Remove viewport metrics, other pageX/pageY behaviors (facebook#9290)

* Remove viewport metrics

event.pageX and event.pageY are in every browser React supports.

* Rerecord tests

Author: nhunzaker

scripts/fiber/tests-passing.txt

@@ -868,7 +868,6 @@ src/renderers/dom/shared/__tests__/ReactBrowserEventEmitter-test.js
 * should work with event plugins without dependencies
 * should work with event plugins with dependencies
 * should bubble onTouchTap
-* should not crash ensureScrollValueMonitoring when createEvent returns null
 
 src/renderers/dom/shared/__tests__/ReactDOM-test.js
 * allows a DOM element to be used with a string

src/renderers/dom/shared/ReactBrowserEventEmitter.js

@@ -13,7 +13,6 @@
 
 var EventPluginRegistry = require('EventPluginRegistry');
 var ReactEventEmitterMixin = require('ReactEventEmitterMixin');
-var ViewportMetrics = require('ViewportMetrics');
 
 var getVendorPrefixedEventName = require('getVendorPrefixedEventName');
 var isEventSupported = require('isEventSupported');
@@ -73,9 +72,7 @@ var isEventSupported = require('isEventSupported');
  *    React Core     .  General Purpose Event Plugin System
  */
 
-var hasEventPageXY;
 var alreadyListeningTo = {};
-var isMonitoringScrollValue = false;
 var reactTopListenersCounter = 0;
 
 // For events like 'submit' which don't consistently bubble (which we trap at a
@@ -344,41 +341,6 @@ var ReactBrowserEventEmitter = Object.assign({}, ReactEventEmitterMixin, {
       handle,
     );
   },
-
-  /**
-   * Protect against document.createEvent() returning null
-   * Some popup blocker extensions appear to do this:
-   * https://github.com/facebook/react/issues/6887
-   */
-  supportsEventPageXY: function() {
-    if (!document.createEvent) {
-      return false;
-    }
-    var ev = document.createEvent('MouseEvent');
-    return ev != null && 'pageX' in ev;
-  },
-
-  /**
-   * Listens to window scroll and resize events. We cache scroll values so that
-   * application code can access them without triggering reflows.
-   *
-   * ViewportMetrics is only used by SyntheticMouse/TouchEvent and only when
-   * pageX/pageY isn't supported (legacy browsers).
-   *
-   * NOTE: Scroll events do not bubble.
-   *
-   * @see http://www.quirksmode.org/dom/events/scroll.html
-   */
-  ensureScrollValueMonitoring: function() {
-    if (hasEventPageXY === undefined) {
-      hasEventPageXY = ReactBrowserEventEmitter.supportsEventPageXY();
-    }
-    if (!hasEventPageXY && !isMonitoringScrollValue) {
-      var refresh = ViewportMetrics.refreshScrollValues;
-      ReactBrowserEventEmitter.ReactEventListener.monitorScrollValue(refresh);
-      isMonitoringScrollValue = true;
-    }
-  },
 });
 
 module.exports = ReactBrowserEventEmitter;

src/renderers/dom/shared/__tests__/ReactBrowserEventEmitter-test.js

@@ -435,20 +435,4 @@ describe('ReactBrowserEventEmitter', () => {
     expect(idCallOrder[1] === PARENT).toBe(true);
     expect(idCallOrder[2] === GRANDPARENT).toBe(true);
   });
-
-  it('should not crash ensureScrollValueMonitoring when createEvent returns null', () => {
-    var originalCreateEvent = document.createEvent;
-    document.createEvent = function() {
-      return null;
-    };
-    spyOn(document, 'createEvent');
-
-    try {
-      var hasEventPageXY = ReactBrowserEventEmitter.supportsEventPageXY();
-      expect(document.createEvent.calls.count()).toBe(1);
-      expect(hasEventPageXY).toBe(false);
-    } finally {
-      document.createEvent = originalCreateEvent;
-    }
-  });
 });

src/renderers/dom/shared/eventPlugins/TapEventPlugin.js

@@ -16,7 +16,6 @@ var EventPluginUtils = require('EventPluginUtils');
 var EventPropagators = require('EventPropagators');
 var SyntheticUIEvent = require('SyntheticUIEvent');
 var TouchEventUtils = require('fbjs/lib/TouchEventUtils');
-var ViewportMetrics = require('ViewportMetrics');
 
 var isStartish = EventPluginUtils.isStartish;
 var isEndish = EventPluginUtils.isEndish;
@@ -74,9 +73,7 @@ function getAxisCoordOfEvent(
   if (singleTouch) {
     return singleTouch[axis.page];
   }
-  return axis.page in nativeEvent
-    ? nativeEvent[axis.page]
-    : nativeEvent[axis.client] + ViewportMetrics[axis.envScroll];
+  return nativeEvent[axis.page];
 }
 
 function getDistance(coords: CoordinatesType, nativeEvent: _Touch): number {

src/renderers/dom/shared/syntheticEvents/SyntheticMouseEvent.js

@@ -12,7 +12,6 @@
 'use strict';
 
 var SyntheticUIEvent = require('SyntheticUIEvent');
-var ViewportMetrics = require('ViewportMetrics');
 
 var getEventModifierState = require('getEventModifierState');
 
@@ -25,6 +24,8 @@ var MouseEventInterface = {
   screenY: null,
   clientX: null,
   clientY: null,
+  pageX: null,
+  pageY: null,
   ctrlKey: null,
   shiftKey: null,
   altKey: null,
@@ -51,17 +52,6 @@ var MouseEventInterface = {
         ? event.toElement
         : event.fromElement);
   },
-  // "Proprietary" Interface.
-  pageX: function(event) {
-    return 'pageX' in event
-      ? event.pageX
-      : event.clientX + ViewportMetrics.currentScrollLeft;
-  },
-  pageY: function(event) {
-    return 'pageY' in event
-      ? event.pageY
-      : event.clientY + ViewportMetrics.currentScrollTop;
-  },
 };
 
 /**

src/renderers/dom/shared/utils/ViewportMetrics.js

@@ -14,7 +14,6 @@
 var DOMLazyTree = require('DOMLazyTree');
 var DOMProperty = require('DOMProperty');
 var React = require('react');
-var ReactBrowserEventEmitter = require('ReactBrowserEventEmitter');
 var ReactCurrentOwner = require('react/lib/ReactCurrentOwner');
 var ReactDOMComponentTree = require('ReactDOMComponentTree');
 var ReactDOMContainerInfo = require('ReactDOMContainerInfo');
@@ -382,7 +381,6 @@ var ReactMount = {
       '_registerComponent(...): Target container is not a DOM element.',
     );
 
-    ReactBrowserEventEmitter.ensureScrollValueMonitoring();
     var componentInstance = instantiateReactComponent(nextElement, false);
 
     if (callback) {