[DevTools] Turn WebInspector.Panel into a web component.

third_party/WebKit/Source/devtools/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//third_party/WebKit/Source/core/core.gni")
 
 devtools_embedder_scripts = [
   "front_end/devtools.js",
   "front_end/Tests.js",
@@ skipping 194 matching lines @@
   "front_end/ui/dropTarget.css",
   "front_end/ui/emptyWidget.css",
   "front_end/ui/filter.css",
   "front_end/ui/infobar.css",
   "front_end/ui/inspectorCommon.css",
   "front_end/ui/inspectorStyle.css",
   "front_end/ui/inspectorSyntaxHighlight.css",
   "front_end/ui/inspectorSyntaxHighlightDark.css",
   "front_end/ui/inspectorViewTabbedPane.css",
   "front_end/ui/listWidget.css",
+  "front_end/ui/panel.css",
   "front_end/ui/panelEnablerView.css",
   "front_end/ui/popover.css",
   "front_end/ui/progressIndicator.css",
   "front_end/ui/radioButton.css",
   "front_end/ui/reportView.css",
   "front_end/ui/rootView.css",
   "front_end/ui/searchableView.css",
   "front_end/ui/slider.css",
   "front_end/ui/softContextMenu.css",
   "front_end/ui/smallBubble.css",
@@ skipping 885 matching lines @@
     deps = [
       ":frontend_protocol_sources",
       ":supported_css_properties",
     ]
     sources = generated_scripts
     outputs = [
       "$resources_out_debug_dir/{{source_file_part}}",
     ]
   }
 }