DevTools: Remove unused variables. Disallow unused variables with eslint

third_party/WebKit/Source/devtools/front_end/main/Main.js

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2007 Matt Lilek (pewtermoose@gmail.com).
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 164 matching lines @@
     Workspace.fileSystemMapping = new Workspace.FileSystemMapping(Workspace.isolatedFileSystemManager);
 
     Main.networkProjectManager = new Bindings.NetworkProjectManager(SDK.targetManager, Workspace.workspace);
     Bindings.presentationConsoleMessageHelper = new Bindings.PresentationConsoleMessageHelper(Workspace.workspace);
     Bindings.cssWorkspaceBinding = new Bindings.CSSWorkspaceBinding(SDK.targetManager, Workspace.workspace);
     Bindings.debuggerWorkspaceBinding = new Bindings.DebuggerWorkspaceBinding(SDK.targetManager, Workspace.workspace);
     Bindings.breakpointManager =
         new Bindings.BreakpointManager(null, Workspace.workspace, SDK.targetManager, Bindings.debuggerWorkspaceBinding);
     Extensions.extensionServer = new Extensions.ExtensionServer();
 
-    var fileSystemWorkspaceBinding =
-        new Persistence.FileSystemWorkspaceBinding(Workspace.isolatedFileSystemManager, Workspace.workspace);
+    new Persistence.FileSystemWorkspaceBinding(Workspace.isolatedFileSystemManager, Workspace.workspace);
     Persistence.persistence =
         new Persistence.Persistence(Workspace.workspace, Bindings.breakpointManager, Workspace.fileSystemMapping);
 
     new Main.OverlayController();
     new Components.ExecutionContextSelector(SDK.targetManager, UI.context);
     Bindings.blackboxManager = new Bindings.BlackboxManager(Bindings.debuggerWorkspaceBinding);
 
     new Main.Main.PauseListener();
     new Main.Main.InspectedNodeRevealer();
     new Main.NetworkPanelIndicator();
@@ skipping 780 matching lines @@
    * @override
    * @return {?Element}
    */
   settingElement() {
     return UI.SettingsUI.createSettingCheckbox(
         Common.UIString('Show rulers'), Common.moduleSetting('showMetricsRulers'));
   }
 };
 
 new Main.Main();