DevTools: fix author shadow dom inspection mode, speacial-case ua. Fix crash from the bug.

Source/devtools/front_end/ElementsPanel.js

Index: Source/devtools/front_end/ElementsPanel.js
diff --git a/Source/devtools/front_end/ElementsPanel.js b/Source/devtools/front_end/ElementsPanel.js
index b58d03aedc54dc0953ff731e475064553df78721..a8bcc33177e101a657c8bc7c336ddf9235554aae 100644
--- a/Source/devtools/front_end/ElementsPanel.js
+++ b/Source/devtools/front_end/ElementsPanel.js
@@ -112,7 +112,7 @@ WebInspector.ElementsPanel = function()
     this._popoverHelper.setTimeout(0);
 
     WebInspector.domAgent.addEventListener(WebInspector.DOMAgent.Events.DocumentUpdated, this._documentUpdatedEvent, this);
-    WebInspector.settings.showShadowDOM.addChangeListener(this._showShadowDOMChanged.bind(this));
+    WebInspector.settings.showUAShadowDOM.addChangeListener(this._showUAShadowDOMChanged.bind(this));
 
     WebInspector.cssModel.addEventListener(WebInspector.CSSStyleModel.Events.ModelWasEnabled, this._updateSidebars, this);
 }
@@ -1128,7 +1128,7 @@ WebInspector.ElementsPanel.prototype = {
         if (!node)
             return;
 
-        node = WebInspector.settings.showShadowDOM.get() ? node : this._leaveUserAgentShadowDOM(node);
+        node = WebInspector.settings.showUAShadowDOM.get() ? node : this._leaveUserAgentShadowDOM(node);
         WebInspector.domAgent.highlightDOMNodeForTwoSeconds(nodeId);
         this.selectDOMNode(node, true);
     },
@@ -1186,7 +1186,7 @@ WebInspector.ElementsPanel.prototype = {
         this._splitVertically(vertically);
     },
 
-    _showShadowDOMChanged: function()
+    _showUAShadowDOMChanged: function()
     {
         this.treeOutline.update();
     },