DevTools: [SSP] force StylesSidebarPane refresh on undo/redo command happens.

Source/devtools/front_end/elements/ElementsPanel.js

Index: Source/devtools/front_end/elements/ElementsPanel.js
diff --git a/Source/devtools/front_end/elements/ElementsPanel.js b/Source/devtools/front_end/elements/ElementsPanel.js
index 3b7d95f882fbf044158b54bf2911d6edbb770142..ffe9beb5bde63c9fd53c67ad03fa21975ee5325a 100644
--- a/Source/devtools/front_end/elements/ElementsPanel.js
+++ b/Source/devtools/front_end/elements/ElementsPanel.js
@@ -709,8 +709,10 @@ WebInspector.ElementsPanel.prototype = {
 
         if (!treeOutline.editing()) {
             handleUndoRedo.call(null, treeOutline);
-            if (event.handled)
+            if (event.handled) {
+                this.sidebarPanes.styles.onUndoOrRedoHappened();
                 return;
+            }
         }
 
         treeOutline.handleShortcut(event);