Don't store a RuleFeatureSet on ScopedStyleResolver.

Don't store a RuleFeatureSet on ScopedStyleResolver.

Instead lets just iterate the list of sheets and ask each one questions. This
shouldn't be much slower since most widgets only have one sheet anyway.

I also moved the media query matching to the sheet collection. We weren't
correctly matching them since we only guarded the feature set, not the
addition to the list of active sheets.

R=abarth@chromium.org, ojan@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/d87602b17cc45a679ecfb9740787418ecc9b83c3

[abarth-chromium, 2015-01-22 00:57:02]

abarth@chromium.org changed reviewers:
+ abarth@chromium.org

[abarth-chromium, 2015-01-22 00:57:03]

lgtm

[esprehn, 2015-01-22 01:00:11]

Committed patchset #3 (id:40001) manually as
d87602b17cc45a679ecfb9740787418ecc9b83c3 (presubmit successful).