[Layout API] Use layoutViewItem() in StyleResolver

Document::layoutView() is deprecated and being removed soon. The
replacement is Document::layoutViewItem(), which routes methods
through the new block layout API. No new API methods were required.

There are no functional changes.

BUG=499321

Review-Url: https://codereview.chromium.org/2124013002
Cr-Commit-Position: refs/heads/master@{#405573}
1 file changed