Don't apply style elements or PIs with loading imports.
updateLayoutTreeIgnorePendingStylesheets may resolve styles when sheets
are loading. For link elements, the main stylesheet is not applied if
any of its @imports are still loading. For style elements and
xml-stylesheets, we did apply the contents of the main stylesheet while
its @imports were loading. That means we applied half-baked stylesheets
and we had an inconsistency between link and style. Instead regard
style elements and processing instructions as loading when @imports are
loading.
BUG=600733
Review URL: https://codereview.chromium.org/1867513002
Cr-Commit-Position: refs/heads/master@{#385564}
7 files changed
