Move preferred stylesheet logic into StyleEngine.
To understand the code better:
We don't support selecting alternate stylesheets in Blink, although the
API for Document.selectedStylesheetSet is present. The way it works, is
that the effective selected stylesheet set is either empty or the
preferred set. Setting selectedStylesheetSet has no effect.
This CL should not impose any functional changes, but a resolverChanged
with no effect has been removed.
The next step for async active stylesheet update is to move the setting
of the preferred set name to where the the dom mutations happen as the
order of mutations is what defines which stylesheet title has
precedence.
BUG=567021
Review URL: https://codereview.chromium.org/1769903002
Cr-Commit-Position: refs/heads/master@{#379762}
7 files changed
