Bug 1405577: Restore the ability to open new windows in new spaces when a window is already in fullscreen mode on macOS. r=mstange

browser/app/macbuild/Contents/Info.plist.in

@@ -238,8 +238,6 @@
 		<key>org.mozilla.updater</key>
 		<string>identifier "org.mozilla.updater" and ((anchor apple generic and certificate leaf[field.1.2.840.113635.100.6.1.9]) or (anchor apple generic and certificate 1[field.1.2.840.113635.100.6.2.6] and certificate leaf[field.1.2.840.113635.100.6.1.13] and certificate leaf[subject.OU] = "43AQ936H96"))</string>
 	</dict>
-  <key>NSDisablePersistence</key>
-  <true/>
   <key>MozillaDeveloperRepoPath</key>
   <string>%MOZ_DEVELOPER_REPO_PATH%</string>
   <key>MozillaDeveloperObjPath</key>

widget/cocoa/nsCocoaWindow.mm

@@ -488,6 +488,11 @@ nsresult nsCocoaWindow::CreateNativeWindow(const NSRect &aRect,
   mWindow = [[windowClass alloc] initWithContentRect:contentRect styleMask:features 
                                  backing:NSBackingStoreBuffered defer:YES];
 
+  // Make sure that window titles don't leak to disk in private browsing mode
+  // due to macOS' resume feature.
+  [mWindow setRestorable:NO];
+  [mWindow disableSnapshotRestoration];
+
   // setup our notification delegate. Note that setDelegate: does NOT retain.
   mDelegate = [[WindowDelegate alloc] initWithGeckoWindow:this];
   [mWindow setDelegate:mDelegate];