Bug 1703404 - use lighter checkmark image for Windows 10 menu checkmarks, r=jaws

Differential Revision: https://phabricator.services.mozilla.com/D111656

toolkit/themes/windows/global/icons/menu-check.svg

@@ -0,0 +1,6 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+<svg width="16" height="16" viewBox="0 0 16 16" xmlns="http://www.w3.org/2000/svg">
+  <path d="M13.8639 3.65609C14.0533 3.85704 14.0439 4.17348 13.8429 4.36288L5.91309 11.8368C5.67573 12.0605 5.30311 12.0536 5.07417 11.8213L2.39384 9.10093C2.20003 8.90422 2.20237 8.58765 2.39907 8.39384C2.59578 8.20003 2.91235 8.20237 3.10616 8.39908L5.51192 10.8407L13.1571 3.63517C13.358 3.44577 13.6745 3.45513 13.8639 3.65609Z" fill="context-fill" fill-opacity="context-fill-opacity"/>
+</svg>

toolkit/themes/windows/global/jar.mn

@@ -31,6 +31,7 @@ toolkit.jar:
   skin/classic/global/dirListing/folder.png                (dirListing/folder.png)
   skin/classic/global/dirListing/up.png                    (dirListing/up.png)
   skin/classic/global/icons/Landscape.png                  (icons/Landscape.png)
+  skin/classic/global/icons/menu-check.svg                 (icons/menu-check.svg)
   skin/classic/global/icons/Portrait.png                   (icons/Portrait.png)
   skin/classic/global/icons/Print-preview.png              (icons/Print-preview.png)
   skin/classic/global/icons/sslWarning.png                 (icons/sslWarning.png)

toolkit/themes/windows/global/menu.css

@@ -376,7 +376,7 @@ menuitem[type="radio"] > .menu-iconic-left > .menu-iconic-icon {
     -moz-context-properties: fill, fill-opacity;
     fill: currentColor;
     fill-opacity: var(--menu-icon-opacity);
-    list-style-image: url("chrome://global/skin/icons/check.svg");
+    list-style-image: url("chrome://global/skin/icons/menu-check.svg");
     width: 16px;
     margin-inline-end: 8px;
   }