GitLab

Adds support for the remaining properties of UrlRequest to
chrome_pdf::BlinkUrlLoader::Open(): the request body, the custom
referrer URL, and whether to ignore redirects.

BlinkUrlLoader::Client now uses a single IsValid() method to check for
missing resources, rather than returning errors from individual methods.
Returning errors from each method complicates the API for no benefit.

MockBlinkUrlLoaderClient has been replaced by FakeBlinkUrlLoaderClient.
The tests no longer assert interactions with BlinkUrlLoader::Client, but
the results of those interactions, so a mock is no longer appropriate.

Additional changes to Open() improve PepperURLLoaderHost compatibility:
The request URL is resolved against the document URL, site-for-cookies
are passed from the document, and service workers are skipped.

Bug: 1099022
Change-Id: If5cbb562ae74efcd3f3807a452e655a893a08eea
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424661Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Daniel Hosseinian <dhoss@chromium.org>
Commit-Queue: K. Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809966}