From c1cfe2881b643f3b4e2017fe5db349936075a4b8 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Thu, 3 Oct 2019 11:55:13 +0200
Subject: [PATCH] [PDFSidebarResizer] Skip the `CSS.supports` checks for
 MOZCENTRAL builds

Since CSS variable support cannot be disabled any more in Firefox, the run-time checks are of no using for MOZCENTRAL builds.
---
 web/pdf_sidebar_resizer.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/web/pdf_sidebar_resizer.js b/web/pdf_sidebar_resizer.js
index 384be23f7..388331054 100644
--- a/web/pdf_sidebar_resizer.js
+++ b/web/pdf_sidebar_resizer.js
@@ -47,8 +47,10 @@ class PDFSidebarResizer {
     this.eventBus = eventBus;
     this.l10n = l10n;
 
-    if (typeof CSS === 'undefined' || typeof CSS.supports !== 'function' ||
-        !CSS.supports(SIDEBAR_WIDTH_VAR, `calc(-1 * ${SIDEBAR_MIN_WIDTH}px)`)) {
+    if ((typeof PDFJSDev === 'undefined' || !PDFJSDev.test('MOZCENTRAL')) &&
+        (typeof CSS === 'undefined' || typeof CSS.supports !== 'function' ||
+         !CSS.supports(SIDEBAR_WIDTH_VAR,
+                       `calc(-1 * ${SIDEBAR_MIN_WIDTH}px)`))) {
       console.warn('PDFSidebarResizer: ' +
                    'The browser does not support resizing of the sidebar.');
       return;