Bug 1835907, part 1 - Add has storage access bit and triggering window id to the LoadInfo - r=smaug,necko-reviewers,kershaw,pbz

In the Storage Access API's latest draft, a few items were added to the user-agent state. Relevant here,
the source snapshot params gained two fields that are initialized from the sourceDocument during
snapshotting source params while navigating: "has storage access" and "environment id".

https://privacycg.github.io/storage-access/#ua-state

These are used to identify self-initiated navigations that come from documents that have obtained storage access.
Combined with a same-origin check, this determines if the destination document of the navigation should start
with storage access.

This is stricter than the current behavior, where if the permission is available, all documents start with storage access.
Instead, now a document will only have storage access if it requests it explicitly or if a same-origin document that has
storage access navigates itself to that document. This is seen as a security win.

Security discussion of this change was here: https://github.com/privacycg/storage-access/issues/113
Artur at Google wrote up a great summary here: https://docs.google.com/document/d/1AsrETl-7XvnZNbG81Zy9BcZfKbqACQYBSrjM3VsIpjY/edit#

Differential Revision: https://phabricator.services.mozilla.com/D184821

docshell/base/nsDocShellLoadState.cpp

@@ -86,6 +86,8 @@ nsDocShellLoadState::nsDocShellLoadState(
   mPrincipalToInherit = aLoadState.PrincipalToInherit();
   mPartitionedPrincipalToInherit = aLoadState.PartitionedPrincipalToInherit();
   mTriggeringSandboxFlags = aLoadState.TriggeringSandboxFlags();
+  mTriggeringWindowId = aLoadState.TriggeringWindowId();
+  mTriggeringStorageAccess = aLoadState.TriggeringStorageAccess();
   mTriggeringRemoteType = aLoadState.TriggeringRemoteType();
   mCsp = aLoadState.Csp();
   mOriginalURIString = aLoadState.OriginalURIString();
@@ -150,6 +152,8 @@ nsDocShellLoadState::nsDocShellLoadState(const nsDocShellLoadState& aOther)
       mResultPrincipalURIIsSome(aOther.mResultPrincipalURIIsSome),
       mTriggeringPrincipal(aOther.mTriggeringPrincipal),
       mTriggeringSandboxFlags(aOther.mTriggeringSandboxFlags),
+      mTriggeringWindowId(aOther.mTriggeringWindowId),
+      mTriggeringStorageAccess(aOther.mTriggeringStorageAccess),
       mCsp(aOther.mCsp),
       mKeepResultPrincipalURIIfSet(aOther.mKeepResultPrincipalURIIfSet),
       mLoadReplace(aOther.mLoadReplace),
@@ -204,6 +208,8 @@ nsDocShellLoadState::nsDocShellLoadState(nsIURI* aURI, uint64_t aLoadIdentifier)
     : mURI(aURI),
       mResultPrincipalURIIsSome(false),
       mTriggeringSandboxFlags(0),
+      mTriggeringWindowId(0),
+      mTriggeringStorageAccess(false),
       mKeepResultPrincipalURIIfSet(false),
       mLoadReplace(false),
       mInheritPrincipal(false),
@@ -443,6 +449,9 @@ nsresult nsDocShellLoadState::CreateFromLoadURIOptions(
   loadState->SetHasValidUserGestureActivation(
       aLoadURIOptions.mHasValidUserGestureActivation);
   loadState->SetTriggeringSandboxFlags(aLoadURIOptions.mTriggeringSandboxFlags);
+  loadState->SetTriggeringWindowId(aLoadURIOptions.mTriggeringWindowId);
+  loadState->SetTriggeringStorageAccess(
+      aLoadURIOptions.mTriggeringStorageAccess);
   loadState->SetPostDataStream(postData);
   loadState->SetHeadersStream(aLoadURIOptions.mHeaders);
   loadState->SetBaseURI(aLoadURIOptions.mBaseURI);
@@ -562,6 +571,23 @@ uint32_t nsDocShellLoadState::TriggeringSandboxFlags() const {
   return mTriggeringSandboxFlags;
 }
 
+void nsDocShellLoadState::SetTriggeringWindowId(uint64_t aTriggeringWindowId) {
+  mTriggeringWindowId = aTriggeringWindowId;
+}
+
+uint64_t nsDocShellLoadState::TriggeringWindowId() const {
+  return mTriggeringWindowId;
+}
+
+void nsDocShellLoadState::SetTriggeringStorageAccess(
+    bool aTriggeringStorageAccess) {
+  mTriggeringStorageAccess = aTriggeringStorageAccess;
+}
+
+bool nsDocShellLoadState::TriggeringStorageAccess() const {
+  return mTriggeringStorageAccess;
+}
+
 bool nsDocShellLoadState::InheritPrincipal() const { return mInheritPrincipal; }
 
 void nsDocShellLoadState::SetInheritPrincipal(bool aInheritPrincipal) {
@@ -1253,6 +1279,8 @@ DocShellLoadStateInit nsDocShellLoadState::Serialize(
   loadState.PrincipalToInherit() = mPrincipalToInherit;
   loadState.PartitionedPrincipalToInherit() = mPartitionedPrincipalToInherit;
   loadState.TriggeringSandboxFlags() = mTriggeringSandboxFlags;
+  loadState.TriggeringWindowId() = mTriggeringWindowId;
+  loadState.TriggeringStorageAccess() = mTriggeringStorageAccess;
   loadState.TriggeringRemoteType() = mTriggeringRemoteType;
   loadState.Csp() = mCsp;
   loadState.OriginalURIString() = mOriginalURIString;