Revert of Enable forced extension updates on NaCl arch mismatch

Revert of Enable forced extension updates on NaCl arch mismatch (patchset #5 id:100001 of https://codereview.chromium.org/516293007/)

Reason for revert:
Chrome OS build with DCHECKs enabled fails on start. This CL breaks assumption, that GAIA extension can be loaded without performing IO-operations.

Original issue's description:
> Enable forced extension updates on NaCl arch mismatch
> 
> This makes extensions aware of the platforms for which
> they have platform-specific resources installed, if any.
> 
> This also hooks up the extension update code with some
> additional logic to place an extension in forced-update
> mode if it has platform-specific resources which don't
> match the current NaCl architecture.
> 
> BUG=409948
> TEST=install an extension which uses NaCl (QuickOffice for example). Rename the _platform-specific/<your-nacl-arch> directory some something else and force an update (e.g. via chrome://extensions button). Observe that a new CRX is downloaded and installed.
> 
> Committed: https://chromium.googlesource.com/chromium/src/+/4a92281fa5d331860d65a59ba45dc882a5c71df4

TBR=sorin@chromium.org,yoz@chromium.org,shuchen@chromium.org,rockot@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=409948
Committed: https://crrev.com/dd6d036ac96067e8613f8c296625d9a049245a32
Cr-Commit-Position: refs/heads/master@{#293128}

[dzhioev (left Google), 2014-09-03 12:44:40]

Created Revert of Enable forced extension updates on NaCl arch mismatch

[commit-bot: I haz the power, 2014-09-03 12:44:58]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dzhioev@chromium.org/532183003/1

[commit-bot: I haz the power, 2014-09-03 12:46:07]

Committed patchset #1 (id:1) as 68bb1aba0c30044640c1c67012ed1c7edd4f9eb0

[commit-bot: I haz the power, 2014-09-10 03:25:29]

Patchset 1 (id:??) landed as
https://crrev.com/dd6d036ac96067e8613f8c296625d9a049245a32
Cr-Commit-Position: refs/heads/master@{#293128}