Revert "Forbid using window properties as global variables" (facebook#2099)

* Revert "Ignore the yarn cache directory (facebook#2063)"

This reverts commit 94149c7.

* Revert "Forbid using window properties as global variables (facebook#1840)"

This reverts commit 5a7d8e8.

Author: gaearon

fixtures/kitchensink/src/App.js

@@ -26,7 +26,7 @@ class BuiltEmitter extends Component {
   }
 
   handleReady() {
-    document.dispatchEvent(new window.Event('ReactFeatureDidMount'));
+    document.dispatchEvent(new Event('ReactFeatureDidMount'));
   }
 
   render() {
@@ -54,7 +54,7 @@ class App extends Component {
   }
 
   componentDidMount() {
-    const feature = window.location.hash.slice(1);
+    const feature = location.hash.slice(1);
     switch (feature) {
       case 'array-destructuring':
         import(

fixtures/kitchensink/src/features/webpack/NoExtInclusion.js

@@ -11,7 +11,7 @@ import React from 'react';
 import aFileWithoutExt from './assets/aFileWithoutExt';
 
 const text = aFileWithoutExt.includes('base64')
-  ? window.atob(aFileWithoutExt.split('base64,')[1]).trim()
+  ? atob(aFileWithoutExt.split('base64,')[1]).trim()
   : aFileWithoutExt;
 
 export default () => (

fixtures/kitchensink/src/features/webpack/UnknownExtInclusion.js

@@ -11,7 +11,7 @@ import React from 'react';
 import aFileWithExtUnknown from './assets/aFileWithExt.unknown';
 
 const text = aFileWithExtUnknown.includes('base64')
-  ? window.atob(aFileWithExtUnknown.split('base64,')[1]).trim()
+  ? atob(aFileWithExtUnknown.split('base64,')[1]).trim()
   : aFileWithExtUnknown;
 
 export default () => (