Introduce Stream::flush [1/2 blink]

Introduce Stream::flush [1/2 blink]

There is no way to flush the buffer in the stream.
This cl introduces Stream::flush method.
We can flush the buffer in the browser process using this method from blink.

We will use this method when we send the data from the ServiceWorker to the browser process progressively.

1/2 blink: https://codereview.chromium.org/747323007/
2/2 chromium: https://codereview.chromium.org/760823002/


BUG=436424
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=186020

[horo, 2014-11-26 02:09:55]

horo@chromium.org changed reviewers:
+ tyoshino@chromium.org

[horo, 2014-11-26 02:09:56]

tyoshino@
Could you please review?

[tyoshino (SeeGerritForStatus), 2014-11-26 05:59:52]

lgtm

[horo, 2014-11-26 06:04:14]

horo@chromium.org changed reviewers:
+ mkwst@chromium.org

[horo, 2014-11-26 06:04:14]

mkwst@
Could you please review this?

[Mike West, 2014-11-26 08:03:50]

LGTM.

[horo, 2014-11-26 08:37:14]

The CQ bit was checked by horo@chromium.org

[commit-bot: I haz the power, 2014-11-26 08:38:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/747323007/1

[commit-bot: I haz the power, 2014-11-26 10:04:34]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=186020