Support data URL for cert-url of Signed HTTP Exchange.

Data URL for cert-url had been supported.
But after which landed in 76.0.3774.0, Chrome failes
to load the data URL when NetworkService is enabled.

To fix this issue, this CL change SignedExchangeCertFetcher to use
DataURLLoaderFactory when the cert-url's scheme is "data:".

Bug: 966736,939871
Change-Id: I352caf29e54f288371f18266597f5374ab7ca2bf
Reviewed-by: Kunihiko Sakamoto <>
Reviewed-by: Kinuko Yasuda <>
Commit-Queue: Tsuyoshi Horo <>
Cr-Commit-Position: refs/heads/master@{#662980}
5 files changed