[CSS Modules] Bypass fetch for Blob URL's #55779
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After switching to Blob URL's in CL:7075691, I noticed that the fetched stylesheet is not always available immediately in a fully declarative scenario (where both the style tag is a module and shadowrootadoptedstylesheets references it), which wasn't the case for dataURI's. Typically, the first n fetches fail to fetch, where n is random. I discovered that dataURI's were always synchronously returned from ResourceFetcher via CreateResourceForStaticData. To match this behavior with Blob URL's, this CL immediately creates a module map entry for a <style type="module"> upon parsing. This entry can then be immediately queried when referenced from the `shadowrootadoptedstylesheets` attribute, avoiding a fetch entirely. DataURI's still need a fetch to generate the underlying object. A test was added that failed ~50% of the time without this change. Bug: 448174611 Change-Id: If50701981f7eaa138fff7d9ca799431c3303fa72 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7093679 Commit-Queue: Kurt Catti-Schmidt <[email protected]> Reviewed-by: Mason Freed <[email protected]> Cr-Commit-Position: refs/heads/main@{#1541305}
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After switching to Blob URL's in CL:7075691, I noticed that the fetched
stylesheet is not always available immediately in a fully declarative
scenario (where both the style tag is a module and
shadowrootadoptedstylesheets references it), which wasn't the case for
dataURI's. Typically, the first n fetches fail to fetch, where n is
random.
I discovered that dataURI's were always synchronously returned from
ResourceFetcher via CreateResourceForStaticData.
To match this behavior with Blob URL's, this CL immediately creates a
module map entry for a style type="module" upon parsing. This entry
can then be immediately queried when referenced from the
shadowrootadoptedstylesheetsattribute, avoiding a fetch entirely.DataURI's still need a fetch to generate the underlying object.
A test was added that failed ~50% of the time without this change.
Bug: 448174611
Change-Id: If50701981f7eaa138fff7d9ca799431c3303fa72
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7093679
Commit-Queue: Kurt Catti-Schmidt <[email protected]>
Reviewed-by: Mason Freed <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1541305}