Hook up prefetcher settings

Summary: This makes use of the previously set up new settings. The logic is a tiny bit difficult to follow so I wanted to make sure it's not lost in the noise of the previous diff.

Reviewed By: jknoxville

Differential Revision: D18036538

fbshipit-source-id: db3bbce4361862cee479aed70578a4bcbde2c46d

src/fb-stubs/Prefetcher.tsx

@@ -7,5 +7,7 @@
  * @format
  */
 
-export default async function setupPrefetcher() {}
+import {Settings} from '../reducers/settings';
+
+export default async function setupPrefetcher(_settings: Settings) {}
 export const shouldInstallPrefetcher = () => false;

src/init.tsx

@@ -77,7 +77,8 @@ const AppFrame = () => {
 };
 
 function setProcessState(store: Store) {
-  const androidHome = store.getState().settingsState.androidHome;
+  const settings = store.getState().settingsState;
+  const androidHome = settings.androidHome;
 
   if (!process.env.ANDROID_HOME) {
     process.env.ANDROID_HOME = androidHome;
@@ -89,6 +90,10 @@ function setProcessState(store: Store) {
     ['emulator', 'tools', 'platform-tools']
       .map(directory => path.resolve(androidHome, directory))
       .join(':') + `:${process.env.PATH}`;
+
+  window.requestIdleCallback(() => {
+    setupPrefetcher(settings);
+  });
 }
 
 function init() {
@@ -96,10 +101,6 @@ function init() {
   initLauncherHooks(config(), store);
   const sessionId = store.getState().application.sessionId;
   initCrashReporter(sessionId || '');
-
-  window.requestIdleCallback(() => {
-    setupPrefetcher();
-  });
 }
 
 // rehydrate app state before exposing init