This change was triggered by the recently added wpt tests that started
failing after auto import:
third_party/blink/web_tests/external/wpt/css/css-images/image-set/image-set-zero-resolution-rendering.html
third_party/blink/web_tests/external/wpt/css/css-images/image-set/image-set-zero-resolution-rendering-2.html

Currently the spec does not restrict the range for resolution,
thus non-positive resolutions are valid and should not be
rejected at parse time.

The current consensus is to parse the non-positive resolutions,
but treat them as unsupported options for rendering purposes.

With this change, image-set will match resolution parsing
with media queries.

An issue has been opend for the spec to define the valid
argument range for resolution:
w3c/csswg-drafts#8532

In the discussion on the issue new proposals were added about
how to treat zero resolutions for rendering purposes. Until the spec
is well defined in this area we will remove the zero resolution
rendering tests.

R=futhark, pdr

Change-Id: I7b329519168f3c088f5c9ee8614931b0ead7a4df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4312883
Commit-Queue: Philip Rogers <pdr@chromium.org>
Commit-Queue: Traian Captan <tcaptan@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1114116}