[DevTools] roll acorn to 5.5.3

New version of acorn support spread and rest operators.

R=dgozman@chromium.org

Bug: chromium:756006
Change-Id: I8c0a5a6d0f39027920f7d0e8b8df42a711262d97
Reviewed-on: https://chromium-review.googlesource.com/956559Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Aleksey Kozyatinskiy <kozyatinskiy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#542031}

third_party/WebKit/LayoutTests/http/tests/devtools/console/console-top-level-await-expected.txt

@@ -82,4 +82,6 @@ let q = 1, s = await 2
 undefined
 s
 2
+await {...{foo: 42}}
+{foo: 42}
 

third_party/WebKit/LayoutTests/http/tests/devtools/console/console-top-level-await.js

@@ -59,6 +59,7 @@
   await test('p');
   await test('let q = 1, s = await 2');
   await test('s');
+  await test('await {...{foo: 42}}');
   await new Promise(resolve => ConsoleTestRunner.waitForRemoteObjectsConsoleMessages(resolve));
   ConsoleTestRunner.dumpConsoleMessages();
   TestRunner.completeTest();

third_party/WebKit/Source/devtools/front_end/formatter_worker/FormatterWorker.js

@@ -100,7 +100,7 @@ FormatterWorker.parseJSONRelaxed = function(content) {
  * @param {string} content
  */
 FormatterWorker.evaluatableJavaScriptSubstring = function(content) {
-  const tokenizer = acorn.tokenizer(content, {ecmaVersion: 8});
+  const tokenizer = acorn.tokenizer(content, {ecmaVersion: 9});
   let result = '';
   try {
     let token = tokenizer.getToken();
@@ -143,7 +143,7 @@ FormatterWorker.evaluatableJavaScriptSubstring = function(content) {
  */
 FormatterWorker.preprocessTopLevelAwaitExpressions = function(content) {
   let wrapped = '(async () => {' + content + '})()';
-  const root = acorn.parse(wrapped, {ecmaVersion: 8});
+  const root = acorn.parse(wrapped, {ecmaVersion: 9});
   const body = root.body[0].expression.callee.body;
   const changes = [];
   let containsAwait = false;
@@ -227,7 +227,7 @@ FormatterWorker.preprocessTopLevelAwaitExpressions = function(content) {
  * @param {string} content
  */
 FormatterWorker.javaScriptIdentifiers = function(content) {
-  const root = acorn.parse(content, {ranges: false, ecmaVersion: 8});
+  const root = acorn.parse(content, {ranges: false, ecmaVersion: 9});
 
   /** @type {!Array<!ESTree.Node>} */
   const identifiers = [];

third_party/WebKit/Source/devtools/front_end/formatter_worker/acorn/AUTHORS

+List of Acorn contributors. Updated before every release.
+
+Adrian Heine
+Adrian Rakovsky
+Alistair Braidwood
+Amila Welihinda
+Andres Suarez
+Angelo
+Aparajita Fishman
+Arian Stolwijk
+Artem Govorov
+Boopesh Mahendran
+Bradley Heinz
+Brandon Mills
+Charles Hughes
+Charmander
+Conrad Irwin
+Daniel Tschinder
+David Bonnet
+Domenico Matteo
+ehmicky
+Felix Maier
+Forbes Lindesay
+Gilad Peleg
+impinball
+Ingvar Stepanyan
+Jackson Ray Hamilton
+Jesse McCarthy
+Jiaxing Wang
+Joel Kemp
+Johannes Herr
+John-David Dalton
+Jordan Klassen
+Jürg Lehni
+Kai Cataldo
+keeyipchan
+Keheliya Gallaba
+Kevin Irish
+Kevin Kwok
+krator
+laosb
+Marek
+Marijn Haverbeke
+Martin Carlberg
+Mat Garcia
+Mathias Bynens
+Mathieu 'p01' Henri
+Matthew Bastien
+Max Schaefer
+Max Zerzouri
+Mihai Bazon
+Mike Rennie
+naoh
+Nicholas C. Zakas
+Nick Fitzgerald
+Olivier Thomann
+Oskar Schöldström
+Paul Harper
+Peter Rust
+PlNG
+Prayag Verma
+ReadmeCritic
+r-e-d
+Richard Gibson
+Rich Harris
+Sebastian McKenzie
+Shahar Soel
+Sheel Bedi
+Simen Bekkhus
+Teddy Katz
+Timothy Gu
+Toru Nagashima
+Victor Homyakov
+Wexpo Lyu
+zsjforcn

third_party/WebKit/Source/devtools/front_end/formatter_worker/acorn/LICENSE

-Copyright (C) 2012-2014 by various contributors (see AUTHORS)
+Copyright (C) 2012-2018 by various contributors (see AUTHORS)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal