Make a copy of HttpResponseHeaders in StreamHandleImpl.

Make a copy of HttpResponseHeaders in StreamHandleImpl.

BufferedResourceHandler passes the response to both the old and the new
handler, so there is a race where the streams logic could access headers on the
UI thread while the old handler (AsyncResourceHandler) is busy modifying them
(via ChromeResourceDispatcherHostDelegate).

BUG=none

Committed: https://crrev.com/ed01b8549fd0a91de7d64015e120a09a30bb8987
Cr-Commit-Position: refs/heads/master@{#295753}

[davidben, 2014-09-19 17:15:43]

davidben@chromium.org changed reviewers:
+ zork@chromium.org

[davidben, 2014-09-19 17:15:44]

Noticed this in trying to sorting out the threading in the PlzNavigate CL.

[Zachary Kuznia, 2014-09-19 18:12:54]

lgtm

[davidben, 2014-09-19 18:18:27]

The CQ bit was checked by davidben@chromium.org

[commit-bot: I haz the power, 2014-09-19 18:19:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/588643002/1

[commit-bot: I haz the power, 2014-09-19 18:55:01]

Committed patchset #1 (id:1) as df7bf622191d98a7b02a67543db9fa5d1087c20e

[commit-bot: I haz the power, 2014-09-19 18:55:40]

Patchset 1 (id:??) landed as
https://crrev.com/ed01b8549fd0a91de7d64015e120a09a30bb8987
Cr-Commit-Position: refs/heads/master@{#295753}