Revert "Post loading tasks on the appropriate WebFrameScheduler's queue."

Revert "Post loading tasks on the appropriate WebFrameScheduler's queue."
and "Fix a UAF in the BackgroundHtmlParser's constructor"

This reverts commit https://crrev.com/f3080498facd16066076e7d459ba7cfda11e582c and https://crrev.com/76d7303845116b1c08bd327c46c99e264b626ada.
(CLs: https://codereview.chromium.org/1366883002 and https://codereview.chromium.org/1391013004.)

Reason: Seems to have broken lots of browser_tests on WinXP.

TBR=jochen@chromium.org

BUG=510398, 538660, 541177
Committed: https://crrev.com/57587e3c7053dc33118ba5a2603879fc6010f6de
Cr-Commit-Position: refs/heads/master@{#353983}

[Marc Treib, 2015-10-13 10:18:26]

treib@chromium.org changed reviewers:
+ alexclarke@chromium.org

[alex clarke (OOO till 29th), 2015-10-13 10:21:30]

lgtm

[Marc Treib, 2015-10-13 10:22:38]

The CQ bit was checked by treib@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-10-13 10:23:10]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402933002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402933002/1

[commit-bot: I haz the power, 2015-10-13 10:38:59]

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

[commit-bot: I haz the power, 2015-10-13 10:39:00]

Dry run: Try jobs failed on following builders:
  android_chromium_gn_compile_dbg on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/android_chromiu...)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[Marc Treib, 2015-10-13 10:53:01]

treib@chromium.org changed reviewers:
+ jochen@chromium.org, sandersd@chromium.org, skyostil@chromium.org

[Marc Treib, 2015-10-13 10:59:19]

The CQ bit was checked by treib@chromium.org

[Marc Treib, 2015-10-13 10:59:19]

The patchset sent to the CQ was uploaded after l-g-t-m from
alexclarke@chromium.org
Link to the patchset: https://codereview.chromium.org/1402933002/#ps20001
(title: "fix bad merge")

[commit-bot: I haz the power, 2015-10-13 11:00:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402933002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402933002/20001

[Marc Treib, 2015-10-13 11:27:00]

The CQ bit was unchecked by treib@chromium.org

[Marc Treib, 2015-10-14 08:25:24]

The CQ bit was checked by treib@chromium.org

[commit-bot: I haz the power, 2015-10-14 08:26:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1402933002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1402933002/20001

[commit-bot: I haz the power, 2015-10-14 08:34:30]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-14 08:35:22]

Patchset 2 (id:??) landed as
https://crrev.com/57587e3c7053dc33118ba5a2603879fc6010f6de
Cr-Commit-Position: refs/heads/master@{#353983}

[Marc Treib, 2015-10-14 12:39:12]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/1402103002/ by treib@chromium.org.

The reason for reverting is: The failures happened again after reverting the
original CL, so relanding that..