Work around for a crasher with the select popup on Mac.

chrome/renderer/render_view.cc

Index: chrome/renderer/render_view.cc
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index f5558ef2298ab4c953c753330097310bf6762047..458ff9c47cb9120e2a619e7684b3d013b0878e86 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -5683,6 +5683,14 @@ void RenderView::OnAsyncFileOpened(base::PlatformFileError error_code,
 
 #if defined(OS_MACOSX)
 void RenderView::OnSelectPopupMenuItem(int selected_index) {
+  if (external_popup_menu_ == NULL) {
+    // Crash reports from the field indicate that we can be notified with a
+    // NULL external popup menu (we probably get notified twice).
+    // If you hit this please file a bug against jcivelli and include the page
+    // and steps to repro.
+    NOTREACHED();
+    return;
+  }
   external_popup_menu_->DidSelectItem(selected_index);
   external_popup_menu_.reset();
 }