Bug 1694140 - [devtools] Add getToolboxForTab and closeToolboxForTab helpers on gDevTools r=ochameau

Depends on D105743

Differential Revision: https://phabricator.services.mozilla.com/D105998

devtools/client/framework/devtools.js

@@ -706,6 +706,20 @@ DevTools.prototype = {
     return TargetFactory.forTab(tab);
   },
 
+  /**
+   * Retrieve an existing toolbox for the provided tab if it was created before.
+   * Returns null otherwise.
+   */
+  async getToolboxForTab(tab) {
+    const target = await this.getTargetForTab(tab);
+    return this._toolboxes.get(target);
+  },
+
+  async closeToolboxForTab(tab) {
+    const target = await this.getTargetForTab(tab);
+    return this.closeToolbox(target);
+  },
+
   /**
    * Compatibility layer for web-extensions. Used by DevToolsShim for
    * browser/components/extensions/ext-devtools.js