Bug 1073826 - Fix isBrowserPrivate on Android (r=margaret)

toolkit/modules/PrivateBrowsingUtils.jsm

@@ -34,7 +34,15 @@ this.PrivateBrowsingUtils = {
   },
 
   isBrowserPrivate: function(aBrowser) {
-    return this.isWindowPrivate(aBrowser.ownerDocument.defaultView);
+    let chromeWin = aBrowser.ownerDocument.defaultView;
+    if (chromeWin.gMultiProcessBrowser) {
+      // In e10s we have to look at the chrome window's private
+      // browsing status since the only alternative is to check the
+      // content window, which is in another process.
+      return this.isWindowPrivate(chromeWin);
+    } else {
+      return this.privacyContextFromWindow(aBrowser.contentWindow).usePrivateBrowsing;
+    }
   },
 
   privacyContextFromWindow: function pbu_privacyContextFromWindow(aWindow) {