StyleSheetContents doesn't need a set of clients.

StyleSheetContents doesn't need a set of clients.

The clients were only used to call clearResolver(), but all clients in Sky
are from the same document, so we can just store the document instead. We
can also use the lifetime of the StyleSheetContents object to manage the
cache in the StyleEngine instead of the list of clients.

R=eseidel@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/f4575b1ecf1cf48e2f7434ba5ae1cf351b344518

[esprehn, 2014-12-17 00:14:15]

esprehn@chromium.org changed reviewers:
+ eseidel@chromium.org, ojan@chromium.org

[eseidel, 2014-12-17 00:20:19]

lgtm

[esprehn, 2014-12-17 00:22:08]

Committed patchset #1 (id:1) manually as
f4575b1ecf1cf48e2f7434ba5ae1cf351b344518 (presubmit successful).