Remove fetching stylesheets with unsupported type
Having deprecated stylesheet links with unsupported MIME types in
https://codereview.chromium.org/1501393003, this patch removes the
capability, updates the affected tests, and removes the UseCounter and
deprecation warning.
This patch also updates the preload scanner to ensure that the resources
are not preloaded, and adds a test to check for this.
BUG=
286682
Committed:
https://crrev.com/9b6d756c09ace8f77dd2c359d891ff34c7d82a04
Cr-Commit-Position: refs/heads/master@{#371708}