Revert of Eliminate silently letting errors pass on pak loading.

Revert of Eliminate silently letting errors pass on pak loading. (patchset #18 id:340001 of https://codereview.chromium.org/537063002/)

Reason for revert:
Causing content_browsertests failures due to pak loading failure.

Original issue's description:
> Eliminate silently letting errors pass on pak loading.
>
> BUG=410411
> TEST=no visible change
>
> Committed: https://crrev.com/03c8c9d936594163d43222a3da0268b3dd9af656
> Cr-Commit-Position: refs/heads/master@{#299717}

TBR=bengr@chromium.org,caitkp@chromium.org,tfarina@chromium.org,tony@chromium.org,avi@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=410411
Committed: https://crrev.com/c52359d6e58c4ff403e9de8be5243f062eff969f
Cr-Commit-Position: refs/heads/master@{#299794}

[dcheng, 2014-10-16 00:31:00]

Created Revert of Eliminate silently letting errors pass on pak loading.

[commit-bot: I haz the power, 2014-10-16 00:33:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/661503003/1

[commit-bot: I haz the power, 2014-10-16 00:36:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-16 00:37:31]

Patchset 1 (id:??) landed as
https://crrev.com/c52359d6e58c4ff403e9de8be5243f062eff969f
Cr-Commit-Position: refs/heads/master@{#299794}