Adds support for nullish coalescing operator

Author: Claudio Procida

gulpfile.js

@@ -48,6 +48,7 @@ var babelOptsJS = {
       rewriteModules: {map: moduleMap},
     }),
   ],
+  plugins: [require('@babel/plugin-proposal-nullish-coalescing-operator')],
 };
 
 var babelOptsFlow = {
@@ -57,6 +58,7 @@ var babelOptsFlow = {
       rewriteModules: {map: moduleMap},
     }),
   ],
+  plugins: [require('@babel/plugin-proposal-nullish-coalescing-operator')],
 };
 
 var COPYRIGHT_HEADER = `/**

meta/bundle-size-stats/Draft.js.json

@@ -32,6 +32,7 @@
     "test-ci": "cross-env NODE_ENV=test npm run lint && npm run flow && npm run test"
   },
   "dependencies": {
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.4.4",
     "fbjs": "^1.0.0",
     "immutable": "~3.7.4",
     "object-assign": "^4.1.0"

meta/bundle-size-stats/Draft.min.js.json

@@ -252,6 +252,14 @@
     "@babel/helper-create-class-features-plugin" "^7.3.4"
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-proposal-nullish-coalescing-operator@^7.4.4":
+  version "7.4.4"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-nullish-coalescing-operator/-/plugin-proposal-nullish-coalescing-operator-7.4.4.tgz#41c360d59481d88e0ce3a3f837df10121a769b39"
+  integrity sha512-Amph7Epui1Dh/xxUxS2+K22/MUi6+6JVTvy3P58tja3B6yKTSjwwx0/d83rF7551D6PVSSoplQb8GCwqec7HRw==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+    "@babel/plugin-syntax-nullish-coalescing-operator" "^7.2.0"
+
 "@babel/plugin-proposal-object-rest-spread@^7.0.0":
   version "7.3.4"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-object-rest-spread/-/plugin-proposal-object-rest-spread-7.3.4.tgz#47f73cf7f2a721aad5c0261205405c642e424654"
@@ -281,6 +289,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-syntax-nullish-coalescing-operator@^7.2.0":
+  version "7.2.0"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-nullish-coalescing-operator/-/plugin-syntax-nullish-coalescing-operator-7.2.0.tgz#f75083dfd5ade73e783db729bbd87e7b9efb7624"
+  integrity sha512-lRCEaKE+LTxDQtgbYajI04ddt6WW0WJq57xqkAZ+s11h4YgfRHhVA/Y2VhfPzzFD4qeLHWg32DMp9HooY4Kqlg==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+
 "@babel/plugin-syntax-object-rest-spread@^7.0.0", "@babel/plugin-syntax-object-rest-spread@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-object-rest-spread/-/plugin-syntax-object-rest-spread-7.2.0.tgz#3b7a3e733510c57e820b9142a6579ac8b0dfad2e"