Bug 1068626 - Don't try to paint a popup widget if we're in e10s and the content process r=jimm

widget/PuppetWidget.cpp

@@ -761,6 +761,14 @@ PuppetWidget::PaintTask::Run()
 bool
 PuppetWidget::NeedsPaint()
 {
+  // e10s popups are handled by the parent process, so never should be painted here
+  if (XRE_GetProcessType() == GeckoProcessType_Content &&
+      Preferences::GetBool("browser.tabs.remote.desktopbehavior", false) &&
+      mWindowType == eWindowType_popup) {
+    NS_WARNING("Trying to paint an e10s popup in the child process!");
+    return false;
+  }
+
   return mVisible;
 }