[DevTools] Do not detach view just to reattach it again in SplitWidget.

third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js

Index: third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js b/third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js
index e313e2b41d86601be4284c8bf6113c25ad02499c..caac11604d4affc93f10b5cd9aa201c1200e843c 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/SplitWidget.js
@@ -150,6 +150,8 @@ WebInspector.SplitWidget.prototype = {
      */
     setMainWidget: function(widget)
     {
+        if (this._mainWidget === widget)
+            return;
         if (this._mainWidget)
             this._mainWidget.detach();
         this._mainWidget = widget;
@@ -166,6 +168,8 @@ WebInspector.SplitWidget.prototype = {
      */
     setSidebarWidget: function(widget)
     {
+        if (this._sidebarWidget === widget)
+            return;
         if (this._sidebarWidget)
             this._sidebarWidget.detach();
         this._sidebarWidget = widget;