Hook up gin platform to blink, and explicitly manage the main thread isolate

Hook up gin platform to blink, and explicitly manage the main thread isolate

We'll soon get rid of the v8 default isolate, so we'll need to manage
our own.

To test the platform implementation, run with
  --js-flags="--noparallel_sweeping --concurrent-sweeping --job-based-sweeping"

BUG=359977
R=dcarney@chromium.org,haraken@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=171036

[haraken, 2014-04-07 12:22:43]

LGTM

[jochen (gone - plz use gerrit), 2014-04-07 17:53:12]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-04-07 17:53:17]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jochen@chromium.org/227653002/1

[commit-bot: I haz the power, 2014-04-07 18:11:08]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-07 18:11:08]

Try jobs failed on following builders:
  tryserver.blink on linux_blink_rel

[jochen (gone - plz use gerrit), 2014-04-08 07:27:41]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2014-04-08 07:27:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/jochen@chromium.org/227653002/1

[commit-bot: I haz the power, 2014-04-08 07:56:24]

Change committed as 171036

[yurys, 2014-04-08 12:36:08]

A revert of this CL has been created in
https://codereview.chromium.org/225023038/ by yurys@chromium.org.

The reason for reverting is: Broke browser_tests on Linux:
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/35802
.