Origin isolation: test location.href access

[chromium-wpt-export-bot]

location.href access is one of the things that is guarded by the
"same-origin domain" check, but it goes down a different code path
than generic synchronous property access such as we test with
window.document. So, it's worth testing it additionally.

Bug: 1042415
Change-Id: I92fc222f895bf25fc1767e7ffddd3d7f7f1f1e86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2255102
Reviewed-by: James MacLean <wjmaclean@chromium.org>
Commit-Queue: Domenic Denicola <domenic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780787}

[wpt-pr-bot]

The review process for this patch is being conducted in the Chromium project.

[LukeZielinski]

Seeing flakiness on Chrome Dev:

Unstable results

Test	Subtest	Results	Messages
/origin-isolation/removing-iframes.sub.https.html		ERROR: 5/10, OK: 5/10
/origin-isolation/removing-iframes.sub.https.html	Before: messageerror event must occur	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	Before: setting document.domain must not give sync access	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	Remove the iframe and insert new ones	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	Parent to child2: messageerror event must occur	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	Parent to child2: setting document.domain must not give sync access	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	Parent to child3: messageerror event must occur	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	Parent to child3: setting document.domain must not give sync access	PASS: 5/10, MISSING: 5/10
/origin-isolation/removing-iframes.sub.https.html	child2 to child3: message event must occur	FAIL: 5/10, MISSING: 5/10	assert_equals: expected "WebAssembly.Module message received" but got "messageerror"
/origin-isolation/removing-iframes.sub.https.html	child2 to child3: setting document.domain must give sync access	FAIL: 5/10, MISSING: 5/10	assert_equals: expected "accessed document successfully" but got "SecurityError"
/origin-isolation/removing-iframes.sub.https.html	child3 to child2: message event must occur	FAIL: 5/10, MISSING: 5/10	assert_equals: expected "WebAssembly.Module message received" but got "messageerror"
/origin-isolation/removing-iframes.sub.https.html	child3 to child2: setting document.domain must give sync access	FAIL: 5/10, MISSING: 5/10	assert_equals: expected "accessed document successfully" but got "SecurityError"

[LukeZielinski]

Filed crbug.com/1097980 @Hexcles could you please admin merge this?