Use real flow types from metro

Summary: Stop ignoring `metro` folder from RN and use their flowtypes correctly

Reviewed By: hramos

Differential Revision: D13085169

fbshipit-source-id: f285223afb7e89ac2c63e53d36be2f3645fa6761

.flowconfig

@@ -22,9 +22,6 @@
 ; Ignore polyfills
 .*/Libraries/polyfills/.*
 
-; Ignore metro
-.*/node_modules/metro/.*
-
 ; These should not be required directly
 ; require from fbjs/lib instead: require('fbjs/lib/invariant')
 .*/node_modules/invariant/.*

.flowconfig.android

@@ -22,9 +22,6 @@
 ; Ignore polyfills
 .*/Libraries/polyfills/.*
 
-; Ignore metro
-.*/node_modules/metro/.*
-
 ; These should not be required directly
 ; require from fbjs/lib instead: require('fbjs/lib/invariant')
 .*/node_modules/invariant/.*

flow-github/metro.js

@@ -8,70 +8,8 @@
  * @format
  */
 
-declare module 'metro' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/HmrServer' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/lib/attachWebsocketServer' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/lib/bundle-modules/HMRClient' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/lib/TerminalReporter' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/Bundler' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/DeltaBundler' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/DeltaBundler/types.flow.js' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/ModuleGraph/types.flow.js' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/lib/getMaxWorkers' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/lib/createModuleIdFactory' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/shared/types.flow' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/lib/reporting' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/Server' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/ModuleGraph/worker/collectDependencies' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/JSTransformer/worker' {
-  declare module.exports: any;
-}
-
-declare module 'metro/src/DeltaBundler/Serializers/plainJSBundle' {
+// metro-visualizer is not listed as a dependency of metro since it pulls a lot
+// of transitive dependencies so we need to tell flow that it may exist.
+declare module 'metro-visualizer' {
   declare module.exports: any;
 }