refactor: make CHROME_GET_MESSAGES handler async (#17148)

lib/browser/chrome-extension.js

@@ -12,6 +12,9 @@ const path = require('path')
 const url = require('url')
 const util = require('util')
 
+const readFile = util.promisify(fs.readFile)
+const writeFile = util.promisify(fs.writeFile)
+
 // Mapping between extensionId(hostname) and manifest.
 const manifestMap = {} // extensionId => manifest
 const manifestNameMap = {} // name => manifest
@@ -232,9 +235,9 @@ const getMessagesPath = (extensionId) => {
   }
 }
 
-ipcMainUtils.handle('CHROME_GET_MESSAGES', function (event, extensionId) {
+ipcMainUtils.handle('CHROME_GET_MESSAGES', async function (event, extensionId) {
   const messagesPath = getMessagesPath(extensionId)
-  return fs.readFileSync(messagesPath)
+  return readFile(messagesPath)
 })
 
 const validStorageTypes = new Set(['sync', 'local'])
@@ -267,9 +270,6 @@ const mkdirp = util.promisify((dir, callback) => {
   })
 })
 
-const readFile = util.promisify(fs.readFile)
-const writeFile = util.promisify(fs.writeFile)
-
 ipcMainUtils.handle('CHROME_STORAGE_READ', async function (event, storageType, extensionId) {
   const filePath = getChromeStoragePath(storageType, extensionId)