From eac15120c652eeff8b70ec668023ad616621327a Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@users.noreply.github.com>
Date: Tue, 23 Jan 2018 17:03:20 +0100
Subject: [PATCH] fix(checkbox): underlying native checkbox being rendered when
 parent uses css column layout (#9258)

Fixes an issue where the hidden native checkbox inside the `mat-checkbox` gets rendered if one of the ancestors is using a CSS column layout.

Fixes #9049.
---
 src/cdk/a11y/_a11y.scss | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/cdk/a11y/_a11y.scss b/src/cdk/a11y/_a11y.scss
index b9bbc4105da..2e67669f09a 100644
--- a/src/cdk/a11y/_a11y.scss
+++ b/src/cdk/a11y/_a11y.scss
@@ -8,6 +8,13 @@
     padding: 0;
     position: absolute;
     width: 1px;
+
+    // Avoid browsers rendering the focus ring in some cases.
+    outline: 0;
+
+    // Avoid some cases where the browser will still render the native controls (see #9049).
+    -webkit-appearance: none;
+    -moz-appearance: none;
   }
 }