Devtools[LayoutEditor]: Rework layout-editor workflow

Source/devtools/front_end/components/InspectElementModeController.js

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * 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
  * notice, this list of conditions and the following disclaimer.
  *
@@ skipping 37 matching lines @@
 
 WebInspector.InspectElementModeController.prototype = {
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetAdded: function(target)
     {
         // When DevTools are opening in the inspect element mode, the first target comes in
         // much later than the InspectorFrontendAPI.enterInspectElementMode event.
-        if (!this.enabled())
+        if (!this.started())
             return;
         var domModel = WebInspector.DOMModel.fromTarget(target);
         domModel.setInspectMode(WebInspector.moduleSetting("showUAShadowDOM").get() ? DOMAgent.InspectMode.SearchForUAShadowDOM : DOMAgent.InspectMode.SearchForNode);
     },
 
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetRemoved: function(target)
     {
     },
 
     /**
      * @return {boolean}
      */
-    enabled: function()
+    started: function()
     {
         return this._toggleSearchButton.toggled();
     },
 
+    stop: function()
+    {
+        if (this.started())
+            this._toggleSearch();
+    },
+
     disable: function()
     {
-        if (this.enabled())
-            this._toggleSearch();
+        this.stop();
+        this._toggleSearchButton.setEnabled(false);
+    },
+
+    enable: function()
+    {
+        this._toggleSearchButton.setEnabled(true);
     },
 
     _toggleSearch: function()
     {
-        var enabled = !this.enabled();
-        this._toggleSearchButton.setToggled(enabled);
+        if (!this._toggleSearchButton.enabled())
+            return;
+
+        var shouldEnable = !this.started();
+        this._toggleSearchButton.setToggled(shouldEnable);
 
         for (var domModel of WebInspector.DOMModel.instances()) {
             var mode;
-            if (!enabled)
+            if (!shouldEnable)
                 mode = DOMAgent.InspectMode.None;
             else if (WebInspector.moduleSetting("showUAShadowDOM").get())
                 mode = DOMAgent.InspectMode.SearchForUAShadowDOM;
             else
                 mode = DOMAgent.InspectMode.SearchForNode;
 
             domModel.setInspectMode(mode);
         }
     },
 
@@ skipping 43 matching lines @@
     {
         if (!WebInspector.inspectElementModeController)
             return null;
 
         return WebInspector.inspectElementModeController._toggleSearchButton;
     }
 }
 
 /** @type {?WebInspector.InspectElementModeController} */
 WebInspector.inspectElementModeController = null;