Index: content/browser/renderer_host/render_widget_host_impl.cc |
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc |
index 543540725d6e35c214fe0ccfdbeb4740422f9a7a..125bf87466c5cb93a209306f94fbd3243713964d 100644 |
--- a/content/browser/renderer_host/render_widget_host_impl.cc |
+++ b/content/browser/renderer_host/render_widget_host_impl.cc |
@@ -1221,6 +1221,9 @@ void RenderWidgetHostImpl::AddKeyboardListener(KeyboardListener* listener) { |
void RenderWidgetHostImpl::RemoveKeyboardListener( |
KeyboardListener* listener) { |
+ // Ensure that the element is actually in the list. |
+ DCHECK(std::find(keyboard_listeners_.begin(), keyboard_listeners_.end(), |
+ listener) != keyboard_listeners_.end()); |
keyboard_listeners_.remove(listener); |
} |