Move browsers to cross-tool config (facebook#3644)

Author: ai

config/webpack.config.dev.js

@@ -200,12 +200,6 @@ module.exports = {
                   plugins: () => [
                     require('postcss-flexbugs-fixes'),
                     autoprefixer({
-                      browsers: [
-                        '>1%',
-                        'last 4 versions',
-                        'Firefox ESR',
-                        'not ie < 9', // React doesn't support IE8 anyway
-                      ],
                       flexbox: 'no-2009',
                     }),
                   ],

config/webpack.config.prod.js

@@ -222,12 +222,6 @@ module.exports = {
                         plugins: () => [
                           require('postcss-flexbugs-fixes'),
                           autoprefixer({
-                            browsers: [
-                              '>1%',
-                              'last 4 versions',
-                              'Firefox ESR',
-                              'not ie < 9', // React doesn't support IE8 anyway
-                            ],
                             flexbox: 'no-2009',
                           }),
                         ],

scripts/init.js

@@ -43,6 +43,13 @@ module.exports = function(
     eject: 'react-scripts eject',
   };
 
+  appPackage.browserslist = [
+    '>1%',
+    'last 4 versions',
+    'Firefox ESR',
+    'not ie < 9',
+  ];
+
   fs.writeFileSync(
     path.join(appPath, 'package.json'),
     JSON.stringify(appPackage, null, 2)