Revert of Cache SubResourceIntegrity checks at Resource

Revert of Cache SubResourceIntegrity checks at Resource (patchset #2 id:20001 of https://codereview.chromium.org/2398733003/ )

Reason for revert:
Reverting due to failing PageLoadMetricsBrowserTest.IgnoreDownloads test starting with this CL.

https://build.chromium.org/p/chromium.win/builders/Win7%20%2832%29%20Tests/builds/10984

Original issue's description:
> Cache SubResourceIntegrity checks at Resource
> 
> Move SubResourceIntegrity check caches from ScriptResource -> Resource.
> This also renames ScriptIntegrityDisposition to generic name ResourceIntegrityDisposition
> 
> This is to prepare for CSSStyleSheetResource to use the same logic.
> Split from https://codereview.chromium.org/2290983003/.
> 
> BUG=642722
> 
> Committed: https://crrev.com/6e09a67eb013cde927f50ac7931018a15bfdb2ba
> Cr-Commit-Position: refs/heads/master@{#423792}

TBR=jww@chromium.org,csharrison@chromium.org,kouhei@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=642722

[nasko, 2016-10-07 17:41:54]

The CQ bit was checked by nasko@chromium.org

[nasko, 2016-10-07 17:41:54]

Created Revert of Cache SubResourceIntegrity checks at Resource

[commit-bot: I haz the power, 2016-10-07 17:42:13]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-07 17:45:14]

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

[commit-bot: I haz the power, 2016-10-07 17:45:17]

Try jobs failed on following builders:
  mac_chromium_compile_dbg_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)