Bug 1916656 - [devtools] Adapt breadcrumb divider for High Contrast Mode. r=devtools-reviewers,ochameau.

The SVG itself is simplified to only take a solid color since that's the case
for all of other icons.

Differential Revision: https://phabricator.services.mozilla.com/D226668

devtools/client/themes/breadcrumbs.css

@@ -103,6 +103,8 @@
   left: -3px;
   margin: 0 4px 0 -1px;
   top: -1px;
+  -moz-context-properties: fill;
+  fill: var(--theme-icon-disabled-color);
 }
 
 .breadcrumbs-widget-item[checked] .breadcrumbs-widget-item-id {

devtools/client/themes/images/breadcrumbs-divider.svg

@@ -2,17 +2,5 @@
    - 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 xmlns="http://www.w3.org/2000/svg" width="5" height="7">
-  <defs>
-    <linearGradient id="b">
-      <stop offset="0" stop-color="#9a9aba"/>
-      <stop offset="1" stop-color="#a6a6c2"/>
-    </linearGradient>
-    <linearGradient id="a">
-      <stop offset="0" stop-color="#8e8eb2"/>
-      <stop offset="1" stop-color="#9a9aba"/>
-    </linearGradient>
-    <linearGradient x1="3.616" y1="3.893" x2="1.285" y2="-.757" id="d" href="#a" gradientUnits="userSpaceOnUse" gradientTransform="matrix(1 0 0 .8684 0 1046.257)"/>
-    <linearGradient x1="2.232" y1="4.162" x2=".629" y2=".966" id="c" href="#b" gradientUnits="userSpaceOnUse" gradientTransform="matrix(1 0 0 .8684 0 1046.257)"/>
-  </defs>
-  <path d="M.2 1045.562l4.6 3.3-4.6 3.3 2-3.3z" fill="url(#c)" stroke="url(#d)" stroke-width=".4" stroke-linejoin="round" transform="translate(0 -1045.362)"/>
+  <path d="M.2 1045.562l4.6 3.3-4.6 3.3 2-3.3z" fill="context-fill" transform="translate(0 -1045.362)"/>
 </svg>