Revert of notify resource caches when pixelref genID goes stale

Revert of notify resource caches when pixelref genID goes stale (patchset #4 id:60001 of https://codereview.chromium.org/825263005/)

Reason for revert:
Crazy failures.

http://build.chromium.org/p/client.skia/builders/Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Debug/builds/1428/steps/dm/logs/stdio

Original issue's description:
> notify resource caches when pixelref genID goes stale
> 
> BUG=skia:
> 
> Committed: https://skia.googlesource.com/skia/+/4675819b9dbb3ad71ec851776e5de26d342f29fe

TBR=bsalomon@google.com,reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Committed: https://skia.googlesource.com/skia/+/90c6bc4e85df2da37f436ea1da203e194c4740e2

[mtklein, 2015-02-19 16:53:02]

Created Revert of notify resource caches when pixelref genID goes stale

[commit-bot: I haz the power, 2015-02-19 16:53:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/936423002/1

[commit-bot: I haz the power, 2015-02-19 16:53:56]

Committed patchset #1 (id:1) as
https://skia.googlesource.com/skia/+/90c6bc4e85df2da37f436ea1da203e194c4740e2