Update webpack prod config (facebook#1181)

Author: Vincenzo Chianese

packages/react-scripts/config/webpack.config.prod.js

@@ -81,6 +81,10 @@ module.exports = {
     // We don't currently advertise code splitting but Webpack supports it.
     filename: 'static/js/[name].[chunkhash:8].js',
     chunkFilename: 'static/js/[name].[chunkhash:8].chunk.js',
+    // Given Webpack supports codesplit and production bundles are using 
+    // subresource integrity, it's important to make sure the attribute
+    // set on async-loaded chunks is set to anonymous.
+    crossOriginLoading: 'anonymous',
     // We inferred the "public path" (such as / or /my-project) from homepage.
     publicPath: publicPath
   },