DevTools: Get rid of WebInspector.panels

LayoutTests/inspector/extensions/extensions-audits-tests.js

 function extension_runAudits(callback)
 {
     evaluateOnFrontend("InspectorTest.startExtensionAudits(reply);", callback);
 }
 
 // runs in front-end
 var initialize_ExtensionsAuditsTest = function()
 {
     InspectorTest.startExtensionAudits = function(callback)
     {
-        const launcherView = WebInspector.panels.audits._launcherView;
+        const launcherView = WebInspector.inspectorView.panel("audits")._launcherView;
         launcherView._selectAllClicked(false);
         launcherView._auditPresentStateElement.checked = true;
 
         var extensionCategories = document.evaluate("label[starts-with(.,'Extension ')]/input[@type='checkbox']",
-            WebInspector.panels.audits._launcherView._categoriesElement, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
+            WebInspector.inspectorView.panel("audits")._launcherView._categoriesElement, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
 
         for (var i = 0; i < extensionCategories.snapshotLength; ++i)
             extensionCategories.snapshotItem(i).click();
 
         function onAuditsDone()
         {
             InspectorTest.runAfterPendingDispatches(function() {
                 InspectorTest.collectAuditResults();
                 callback();
             });
         }
-        InspectorTest.addSniffer(WebInspector.panels.audits, "auditFinishedCallback", onAuditsDone, true);
+        InspectorTest.addSniffer(WebInspector.inspectorView.panel("audits"), "auditFinishedCallback", onAuditsDone, true);
 
         launcherView._launchButtonClicked();
     }
 
     InspectorTest.dumpAuditProgress = function()
     {
         var progress = document.querySelector(".panel.audits progress");
         InspectorTest.addResult("Progress: " + Math.round(100 * progress.value / progress.max) + "%");
     }
 
     WebInspector.inspectorView.showPanel("audits");
 }