Do not keep InvalidationSets on the Oilpan heap.

Do not keep InvalidationSets on the Oilpan heap.

An InvalidationSet keeps sets of names/strings and tend to have lifetimes
that track those of RuleFeatureSets and not be shared.

Hence it doesn't meet the bar for being on the Oilpan heap; for workloads
where invalidations happen frequently, having them on the heap just causes
unnecessary follow-on work in having to sweep out at some later GC.

Trivially tidy up StyleResolver construction as part of this CL also.

R=haraken
BUG=

Committed: https://crrev.com/dfa5b5b187a2ced692253672b963a3acb790eb24
Cr-Commit-Position: refs/heads/master@{#352829}

[sof, 2015-10-07 12:42:13]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2015-10-07 12:42:14]

please take a look.

[haraken, 2015-10-07 13:02:39]

LGTM

[sof, 2015-10-07 13:19:14]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-10-07 13:20:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1389333003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1389333003/1

[commit-bot: I haz the power, 2015-10-07 14:23:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-07 14:23:59]

Patchset 1 (id:??) landed as
https://crrev.com/dfa5b5b187a2ced692253672b963a3acb790eb24
Cr-Commit-Position: refs/heads/master@{#352829}