Bug 1597499 - Make Session Restore work in Fission, r=nika

Differential Revision: https://phabricator.services.mozilla.com/D107883

docshell/base/nsDocShell.cpp

@@ -6555,6 +6555,12 @@ nsresult nsDocShell::EndPageLoad(nsIWebProgress* aProgress,
   //
   nsCOMPtr<nsIDocShell> kungFuDeathGrip(this);
 
+  // We'll never need to restore data into an about:blank document, so we can
+  // ignore those here.
+  if (!NS_IsAboutBlank(url)) {
+    MaybeRestoreTabContent();
+  }
+
   // Notify the ContentViewer that the Document has finished loading.  This
   // will cause any OnLoad(...) and PopState(...) handlers to fire.
   if (!mEODForCurrentDocument && mContentViewer) {
@@ -13304,6 +13310,23 @@ void nsDocShell::NotifyJSRunToCompletionStop() {
   }
 }
 
+void nsDocShell::MaybeRestoreTabContent() {
+  BrowsingContext* bc = mBrowsingContext;
+  if (bc && bc->Top()->GetHasRestoreData()) {
+    if (XRE_IsParentProcess()) {
+      if (WindowGlobalParent* wgp = bc->Canonical()->GetCurrentWindowGlobal()) {
+        bc->Canonical()->RequestRestoreTabContent(wgp);
+      }
+    } else {
+      if (WindowContext* windowContext = bc->GetCurrentWindowContext()) {
+        if (WindowGlobalChild* wgc = windowContext->GetWindowGlobalChild()) {
+          wgc->SendRequestRestoreTabContent();
+        }
+      }
+    }
+  }
+}
+
 /* static */
 void nsDocShell::MaybeNotifyKeywordSearchLoading(const nsString& aProvider,
                                                  const nsString& aKeyword) {