DevTools: bring back existing panel selection rendering (border image)

Source/devtools/front_end/components/inspectorViewTabbedPane.css

Index: Source/devtools/front_end/components/inspectorViewTabbedPane.css
diff --git a/Source/devtools/front_end/components/inspectorViewTabbedPane.css b/Source/devtools/front_end/components/inspectorViewTabbedPane.css
index 46db1bf34bae1231ce88dd15725a59976692bae3..7757a50dca1864e3369bc24e8b74c42809b1bb89 100644
--- a/Source/devtools/front_end/components/inspectorViewTabbedPane.css
+++ b/Source/devtools/front_end/components/inspectorViewTabbedPane.css
@@ -10,10 +10,6 @@
     overflow: visible;
 }
 
-.tabbed-pane-header-tab {
-    transition: background-color 100ms cubic-bezier(0.4, 0, 0.2, 1);
-}
-
 .tabbed-pane-header-tab:hover {
     background-color: rgba(105, 105, 105, 0.1) !important;
 }
@@ -24,8 +20,9 @@
     margin: 0;
     background: none;
     border: none;
+    border-left: 2px solid transparent;
+    border-right: 2px solid transparent;
     padding: 0 6px;
-    transition: background-color 150ms cubic-bezier(0, 0, 0.2, 1);
 }
 
 .tabbed-pane-header-tab {
@@ -34,4 +31,6 @@
 
 .tabbed-pane-header-tab.selected {
     color: #333;
+    border-width: 0 2px 0 2px;
+    -webkit-border-image: url(Images/toolbarItemSelected.png) 0 2 0 2;
 }