commit 9277dfc597167e684a25a8240059159d550d2aa6
author Nasko Oskov <nasko@chromium.org> Mon Sep 17 23:20:54 2018
committer Commit Bot <commit-bot@chromium.org> Mon Sep 17 23:20:54 2018
tree dfa1686b8e16fffd7fef5e7f90d4647f805c1ce7
parent e642495a7290f858940e248bf72a81e13d1c4a2b

Allow an opaque url::Origin to remember where it came from.

The problem being solved here is that, although various web platform features
can cause documents to be placed in opaque origins, sometimes doing so
obscures the actual source of the documents, which itself can be a
security risk. "data:" URLs, "srcdoc" plus "sandbox" are particular tricky cases
of this, as neither the URL nor the committed origin retains information about
which network host the content is originally from.

This CL is the first step towards solving this problem by keeping that
information around in url::Origin. It is just the url::Origin changes
from nick@'s work on precursor origins started in https://crrev.com/c/1028985.

The precursor information must be used carefully. Opaque origins should
generally not inherit privileges from the origins they derive from. However, in
some cases (such as restrictions on process placement, or determining the http
lock icon, or determining content script injection) this information may be
relevant to ensure that entering an opaque origin does not grant privileges
initially denied to the original non-opaque origin.

This new tracking is transitive: meaning if a page loaded from
http://example.com navigates to a data URL, which then navigates to a blob:null
URL, which embeds an <iframe sandbox srcdoc="...">, the precursor origin for the
sandboxed iframe is retained to be "http://example.com".

Bug: 882053
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I021245c624b78f08bd835c5cae9fde7ec5e44b80
Reviewed-on: https://chromium-review.googlesource.com/1214745
Commit-Queue: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Ian Clelland <iclelland@chromium.org>
Reviewed-by: Luna Lu <loonybear@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591867}