Rename test files for TaskWorklet and WorkerTaskQueue

This CL renames test files for TaskWorklet and WorkerTaskQueue from foo_bar.html
to foo-bar.html based on the layout tests guide:

"File names should use snake-case, but preserve the case of any embedded API
names. For example, prefer document-createElement.html to
document-create-element.html."
https://chromium.googlesource.com/chromium/src/+/HEAD/docs/testing/layout_tests_tips.md#file-names

Bug: 879306
Change-Id: I704665e48c3697205f079a2d2ba28428aa0cffa5
Reviewed-on: https://chromium-review.googlesource.com/c/1334673Reviewed-by: Nate Chapin <japhet@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608304}

third_party/WebKit/LayoutTests/http/tests/workers/taskqueue/taskWorklet_with_async_process.html → third_party/WebKit/LayoutTests/http/tests/workers/taskqueue/taskWorklet-with-async-process.html

@@ -3,7 +3,7 @@
 <script src="../../../resources/testharnessreport.js"></script>
 <script>
 promise_test(async () => {
-  await taskWorklet.addModule("resources/async_sum.js");
+  await taskWorklet.addModule("resources/async-sum.js");
   const task = taskWorklet.postTask('repeat', 2);
   const task2 = taskWorklet.postTask('repeat', 4);
   const task3 = taskWorklet.postTask('sum', task, task2);