In part 1, I understood the need and could tell when and where to make changes, but in this patch, I'm not sure about it at all. I blindly copied every CSP change/inhertance, but in all honesty, I'm not sure which ones we need and which ones we don't.

I also haven't covered all the codepaths. The following are still missing (and these are the ones I could trace, there could be even more):

• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/base/nsDocShell.cpp#12897
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/base/nsDocShellLoadState.cpp#486
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/shistory/SessionHistoryEntry.cpp#269
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/shistory/nsSHEntry.cpp#925
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/shistory/nsSHistory.cpp#2403
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/dom/base/LocationBase.cpp#104
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/dom/base/nsFrameLoader.cpp#687
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/dom/base/nsFrameLoader.cpp#690
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/dom/base/nsObjectLoadingContent.cpp#1462
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/dom/clients/manager/ClientNavigateOpChild.cpp#254
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/dom/html/HTMLFormElement.cpp#883
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/netwerk/ipc/DocumentLoadListener.cpp#2543
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/toolkit/components/windowwatcher/nsWindowWatcher.cpp#1351
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/base/nsDocShell.cpp#8384
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/base/nsDocShell.cpp#10068
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/base/nsDocShell.cpp#10292
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/docshell/shistory/SessionHistoryEntry.cpp#58
• https://searchfox.org/mozilla-central/rev/19764d620c02025bdcc8d1f3c4fcf5a580407a01/netwerk/ipc/DocumentChannelChild.cpp#242

Well I'm glad no one is cc'd on this bug.. My moz-phab is acting up, sorry for the disturbance.

This patch is loaded with multiple changes. I couldn't really split it. Sorry :/

In summary

1. Added CORSMode to LoadInfo. It is only populated in ScriptLoader. When we want to extend this, we will need to do the same for other destinations.
2. About using the request mode instead of CORS mode, I looked into it and it looks like we compute security flags based on CORS mode and pass it into nsIChannel. We could change content policy check method to something similar to ProcessCrossOriginResourcePolicyHeader, and get request mode there, but then we'll lose other properties. I could be wrong, but I think this method is good enough.
3. Changed IntegrityPolicy::ShouldLoad a bit. It now matches 100% with the spec and Chrome's implementation.

Comment on attachment 9488363 [details]
WIP: Bug 1960904 - Add RequestMode to LoadInfo

Revision D249807 was moved to bug 1966691. Setting attachment 9488363 [details] to obsolete.

Comment on attachment 9488364 [details]
WIP: Bug 1960904 - Set request mode for script loads

Revision D249808 was moved to bug 1966691. Setting attachment 9488364 [details] to obsolete.

Comment on attachment 9487042 [details]
Bug 1960904 - Prototype PolicyContainer r=tschuster

Revision D248908 was moved to bug 1968607. Setting attachment 9487042 [details] to obsolete.

Comment on attachment 9487101 [details]
Bug 1960904 - Populate PolicyContainer in Document r=tschuster

Revision D248949 was moved to bug 1968607. Setting attachment 9487101 [details] to obsolete.

Comment on attachment 9487560 [details]
Bug 1960904 - Part 1: Copy PolicyContainer Similar to CSP r=tschuster

Revision D249248 was moved to bug 1968607. Setting attachment 9487560 [details] to obsolete.

Comment on attachment 9488443 [details]
Bug 1960904 - Part 2: Copy PolicyContainer Similar to CSP r=tschuster

Revision D249868 was moved to bug 1968607. Setting attachment 9488443 [details] to obsolete.

Comment on attachment 9489093 [details]
Bug 1960904 - Part 3: Copy PolicyContainer Similar to CSP r=tschuster

Revision D250286 was moved to bug 1968607. Setting attachment 9489093 [details] to obsolete.