The feature was deprecated in M49 and flagged off in M50.
This patch removes it entirely from the codebase.

Review URL: https://codereview.chromium.org/1909433003

Cr-Commit-Position: refs/heads/master@{#35714}

To avoid tanking context startup performance, only the actual installation of the
JS-exposed API is flag-guarded. The remainder of the implementation still
resides in the snapshot.

Review URL: https://codereview.chromium.org/1257063003

Cr-Commit-Position: refs/heads/master@{#30017}

R=jochen@chromium.org
BUG=

Review URL: https://codereview.chromium.org/266243003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21173 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

> R=mstarzinger@chromium.org
> BUG=
>
> Committed: https://code.google.com/p/v8/source/detail?r=20211
>
> Review URL: https://codereview.chromium.org/206163004

R=rossberg@chromium.org
TBR=rossberg@chromium.org
LOG=y
BUG=n

Review URL: https://codereview.chromium.org/219303002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20353 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=mstarzinger@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=20211

Review URL: https://codereview.chromium.org/206163004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20313 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Reason: breaks Blink layout tests.

R=machenbach@chromium.org
BUG=

Review URL: https://codereview.chromium.org/210853003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20233 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=mstarzinger@chromium.org
BUG=

Review URL: https://codereview.chromium.org/206163004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20211 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This patch generalizes Object.observe callbacks and promise resolution into a FIFO queue called a "microtask queue".

It also exposes new V8 API which exposes the microtask queue to the embedder. In particular, it allows the embedder to

-schedule a microtask (EnqueueExternalMicrotask)
-run the microtask queue (RunMicrotasks)
-control whether the microtask queue is run automatically within V8 when the last script exits (SetAutorunMicrotasks).

R=dcarney@chromium.org, rossberg@chromium.org, dcarney, rossberg, svenpanne
BUG=

Review URL: https://codereview.chromium.org/154283002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19344 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=adamk,rossberg
BUG=

Review URL: https://codereview.chromium.org/150103012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19176 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=rossberg@chromium.org, rossberg
BUG=

Review URL: https://codereview.chromium.org/131413008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19084 ce2b1a6d-e550-0410-aec6-3dcde31c8c00