In particular, async functions used to return the intermediate "throwaway" promise, which both causes a memory leak and is incompatible with part of catch prediction. However, returning the outer Promise leads to a different async callstack than when it is not included, namely that there are no lines on the stack trace for the previous lines in the file (only for the actual call stack). This affects virtual/asyncawait/inspector/sources/debugger-async/async-await/async-callstack-async-await3.html , which will need a NeedsManualRebaseline .

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/65f3eb996d557b85e434f74e9d8dd5a14af29c9c

commit 65f3eb996d557b85e434f74e9d8dd5a14af29c9c
Author: littledan <littledan@chromium.org>
Date: Thu Sep 15 01:11:35 2016

NeedsManualRebaseline for async/await stack trace test

BUG= chromium:646199 

Review-Url: https://codereview.chromium.org/2340583004
Cr-Commit-Position: refs/heads/master@{#418738}

[modify] https://crrev.com/65f3eb996d557b85e434f74e9d8dd5a14af29c9c/third_party/WebKit/LayoutTests/TestExpectations

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ce1a9526d762f50324b4202a32eebe085b810cc8

commit ce1a9526d762f50324b4202a32eebe085b810cc8
Author: littledan <littledan@chromium.org>
Date: Fri Sep 23 23:20:36 2016

New test expectations for async function callstack tests

Async/await functions are getting better stack traces from the V8
patch at https://codereview.chromium.org/2357423002/ . This patch
checks in new test expectations and marks the tests as
NeedsManualRebaseline until the V8 patch is checked in and the roll
occurs.

BUG= v8:4483 , chromium:646199 

Review-Url: https://codereview.chromium.org/2362923002
Cr-Commit-Position: refs/heads/master@{#420778}

[modify] https://crrev.com/ce1a9526d762f50324b4202a32eebe085b810cc8/third_party/WebKit/LayoutTests/TestExpectations
[modify] https://crrev.com/ce1a9526d762f50324b4202a32eebe085b810cc8/third_party/WebKit/LayoutTests/inspector/sources/debugger-async/async-await/async-callstack-async-await1-expected.txt
[modify] https://crrev.com/ce1a9526d762f50324b4202a32eebe085b810cc8/third_party/WebKit/LayoutTests/inspector/sources/debugger-async/async-await/async-callstack-async-await2-expected.txt
[modify] https://crrev.com/ce1a9526d762f50324b4202a32eebe085b810cc8/third_party/WebKit/LayoutTests/inspector/sources/debugger-async/async-await/async-callstack-async-await3-expected.txt

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bbb2130606361e1f25c89822ccbe64942ee9c0cc

commit bbb2130606361e1f25c89822ccbe64942ee9c0cc
Author: littledan <littledan@chromium.org>
Date: Mon Sep 26 20:26:17 2016

Remove NeedsManualRebaseline from async/await stack trace tests

BUG= chromium:646199 

Review-Url: https://codereview.chromium.org/2375503002
Cr-Commit-Position: refs/heads/master@{#420978}

[modify] https://crrev.com/bbb2130606361e1f25c89822ccbe64942ee9c0cc/third_party/WebKit/LayoutTests/TestExpectations