From b63fa8f9298ab69176cf826289debb593ba94703 Mon Sep 17 00:00:00 2001
From: Tetsuharu OHZEKI <tetsuharu.ohzeki@gmail.com>
Date: Sun, 2 Feb 2020 16:53:54 +0000
Subject: [PATCH] Bug 1597475 - Fix uses of nsIDocShellTreeItem in
 nsDocumentViewer::GetContentSize(). r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D61415

--HG--
extra : moz-landing-system : lando
---
 layout/base/nsDocumentViewer.cpp | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/layout/base/nsDocumentViewer.cpp b/layout/base/nsDocumentViewer.cpp
index 6dcd47ebad30..dfed89ff72e1 100644
--- a/layout/base/nsDocumentViewer.cpp
+++ b/layout/base/nsDocumentViewer.cpp
@@ -18,6 +18,7 @@
 #include "nsIContent.h"
 #include "nsIContentViewer.h"
 #include "nsIDocumentViewerPrint.h"
+#include "mozilla/dom/BrowsingContext.h"
 #include "mozilla/dom/BeforeUnloadEvent.h"
 #include "mozilla/dom/PopupBlocker.h"
 #include "mozilla/dom/Document.h"
@@ -3171,16 +3172,14 @@ nsresult nsDocumentViewer::GetContentSizeInternal(int32_t* aWidth,
 
 NS_IMETHODIMP
 nsDocumentViewer::GetContentSize(int32_t* aWidth, int32_t* aHeight) {
-  // Skip doing this on docshell-less documents for now
-  nsCOMPtr<nsIDocShellTreeItem> docShellAsItem(mContainer);
-  NS_ENSURE_TRUE(docShellAsItem, NS_ERROR_NOT_AVAILABLE);
+  NS_ENSURE_TRUE(mContainer, NS_ERROR_NOT_AVAILABLE);
 
-  nsCOMPtr<nsIDocShellTreeItem> docShellParent;
-  docShellAsItem->GetInProcessSameTypeParent(getter_AddRefs(docShellParent));
+  RefPtr<BrowsingContext> bc = mContainer->GetBrowsingContext();
+  NS_ENSURE_TRUE(bc, NS_ERROR_NOT_AVAILABLE);
 
   // It's only valid to access this from a top frame.  Doesn't work from
   // sub-frames.
-  NS_ENSURE_TRUE(!docShellParent, NS_ERROR_FAILURE);
+  NS_ENSURE_TRUE(bc->IsTop(), NS_ERROR_FAILURE);
 
   return GetContentSizeInternal(aWidth, aHeight, NS_UNCONSTRAINEDSIZE,
                                 NS_UNCONSTRAINEDSIZE);