Attach nsGlobalWindow's title property to the primary content document's title property. b=41984, r=jst

dom/src/base/nsGlobalWindow.cpp

@@ -978,37 +978,50 @@ GlobalWindowImpl::SetLocation(jsval aLocation)
 NS_IMETHODIMP    
 GlobalWindowImpl::GetTitle(nsAWritableString& aTitle)
 {
-  aTitle.Truncate();  
-  if (mDocShell) {
+  aTitle.Truncate();
+
+  nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(do_QueryInterface(mDocShell));
+  if (docShellAsItem) {
     // See if we're a chrome shell.
     PRInt32 type;
-    nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(do_QueryInterface(mDocShell));
     docShellAsItem->GetItemType(&type);
     if(type == nsIDocShellTreeItem::typeChrome) {
-      nsCOMPtr<nsIBaseWindow> docShellAsWin(do_QueryInterface(mDocShell));
-      if(docShellAsWin) {
-        nsXPIDLString title;
-        docShellAsWin->GetTitle(getter_Copies(title));
-        
-        aTitle.Assign(title);
+      nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
+      GetTreeOwner(getter_AddRefs(treeOwner));
+      if (treeOwner) {
+        nsCOMPtr<nsIDocShellTreeItem> primaryContent;
+        treeOwner->GetPrimaryContentShell(getter_AddRefs(primaryContent));
+        nsCOMPtr<nsIBaseWindow> docShellAsWin(do_QueryInterface(primaryContent));
+        if (docShellAsWin) {
+          nsXPIDLString title;
+          docShellAsWin->GetTitle(getter_Copies(title));
+          aTitle.Assign(title);
+        }
       }
     }
   }
+
   return NS_OK;
 }
 
 NS_IMETHODIMP    
 GlobalWindowImpl::SetTitle(const nsAReadableString& aTitle)
 {
-  if(mDocShell) {
+  nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(do_QueryInterface(mDocShell));
+  if(docShellAsItem) {
     // See if we're a chrome shell.
     PRInt32 type;
-    nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(do_QueryInterface(mDocShell));
     docShellAsItem->GetItemType(&type);
     if(type == nsIDocShellTreeItem::typeChrome) {
-      nsCOMPtr<nsIBaseWindow> docShellAsWin(do_QueryInterface(mDocShell));
-      if(docShellAsWin) {
-        docShellAsWin->SetTitle(nsPromiseFlatString(aTitle));
+      nsCOMPtr<nsIDocShellTreeOwner> treeOwner;
+      GetTreeOwner(getter_AddRefs(treeOwner));
+      if (treeOwner) {
+        nsCOMPtr<nsIDocShellTreeItem> primaryContent;
+        treeOwner->GetPrimaryContentShell(getter_AddRefs(primaryContent));
+        nsCOMPtr<nsIBaseWindow> docShellAsWin(do_QueryInterface(primaryContent));
+        if (docShellAsWin) {
+          docShellAsWin->SetTitle(nsPromiseFlatString(aTitle));
+        }
       }
     }
   }