diff --git a/dom/ipc/ContentParent.cpp b/dom/ipc/ContentParent.cpp
index c2b8901137f..60043bc2f19 100644
--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -87,6 +87,8 @@
 #include "StructuredCloneUtils.h"
 #include "TabParent.h"
 #include "URIUtils.h"
+#include "nsIWebBrowserChrome.h"
+#include "nsIDocShell.h"
 
 #ifdef ANDROID
 # include "gfxAndroidPlatform.h"
@@ -419,10 +421,29 @@ ContentParent::CreateBrowserOrApp(const TabContext& aContext,
         if (nsRefPtr<ContentParent> cp = GetNewOrUsed(aContext.IsBrowserElement())) {
             nsRefPtr<TabParent> tp(new TabParent(aContext));
             tp->SetOwnerElement(aFrameElement);
+            uint32_t chromeFlags = 0;
+
+            // Propagate the private-browsing status of the element's parent
+            // docshell to the remote docshell, via the chrome flags.
+            nsCOMPtr<Element> frameElement = do_QueryInterface(aFrameElement);
+            MOZ_ASSERT(frameElement);
+            nsIDocShell* docShell =
+                frameElement->OwnerDoc()->GetWindow()->GetDocShell();
+            MOZ_ASSERT(docShell);
+            nsCOMPtr<nsILoadContext> loadContext = do_QueryInterface(docShell);
+            if (loadContext && loadContext->UsePrivateBrowsing()) {
+                chromeFlags |= nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW;
+            }
+            bool affectLifetime;
+            docShell->GetAffectPrivateSessionLifetime(&affectLifetime);
+            if (affectLifetime) {
+                chromeFlags |= nsIWebBrowserChrome::CHROME_PRIVATE_LIFETIME;
+            }
+
             PBrowserParent* browser = cp->SendPBrowserConstructor(
                 tp.forget().get(), // DeallocPBrowserParent() releases this ref.
                 aContext.AsIPCTabContext(),
-                /* chromeFlags */ 0);
+                chromeFlags);
             return static_cast<TabParent*>(browser);
         }
         return nullptr;
diff --git a/dom/ipc/TabChild.cpp b/dom/ipc/TabChild.cpp
index bf7b04052be..22e9b39470d 100644
--- a/dom/ipc/TabChild.cpp
+++ b/dom/ipc/TabChild.cpp
@@ -688,6 +688,14 @@ TabChild::Init()
 
   nsCOMPtr<nsIDocShell> docShell = do_GetInterface(mWebNav);
   MOZ_ASSERT(docShell);
+
+  docShell->SetAffectPrivateSessionLifetime(
+      mChromeFlags & nsIWebBrowserChrome::CHROME_PRIVATE_LIFETIME);
+  nsCOMPtr<nsILoadContext> loadContext = do_GetInterface(mWebNav);
+  MOZ_ASSERT(loadContext);
+  loadContext->SetPrivateBrowsing(
+      mChromeFlags & nsIWebBrowserChrome::CHROME_PRIVATE_WINDOW);
+
   nsCOMPtr<nsIWebProgress> webProgress = do_GetInterface(docShell);
   NS_ENSURE_TRUE(webProgress, NS_ERROR_FAILURE);
   webProgress->AddProgressListener(this, nsIWebProgress::NOTIFY_LOCATION);
diff --git a/embedding/browser/webBrowser/nsIWebBrowserChrome.idl b/embedding/browser/webBrowser/nsIWebBrowserChrome.idl
index a7d3cb27949..efa6b7a6229 100644
--- a/embedding/browser/webBrowser/nsIWebBrowserChrome.idl
+++ b/embedding/browser/webBrowser/nsIWebBrowserChrome.idl
@@ -69,8 +69,13 @@ interface nsIWebBrowserChrome : nsISupports
     // flags are specified, the opened window will inherit the privacy
     // status of its opener.  If there is no opener window, the new
     // window will be non-private.
+    //
+    // CHROME_PRIVATE_LIFETIME causes the docshell to affect private-browsing
+    // session lifetime.  This flag is currently respected only for remote
+    // docshells.
     const unsigned long CHROME_PRIVATE_WINDOW         = 0x00010000;
     const unsigned long CHROME_NON_PRIVATE_WINDOW     = 0x00020000;
+    const unsigned long CHROME_PRIVATE_LIFETIME       = 0x00040000;
 
     // Prevents new window animations on Mac OS X Lion.  Ignored on other
     // platforms.