DevTools: bake generic css files into the concatenated one.

Source/devtools/front_end/ui/SplitView.js

 /*
  * Copyright (C) 2012 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 22 matching lines @@
  * @param {boolean} secondIsSidebar
  * @param {string=} settingName
  * @param {number=} defaultSidebarWidth
  * @param {number=} defaultSidebarHeight
  * @param {boolean=} constraintsInDip
  */
 WebInspector.SplitView = function(isVertical, secondIsSidebar, settingName, defaultSidebarWidth, defaultSidebarHeight, constraintsInDip)
 {
     WebInspector.View.call(this);
 
-    this.registerRequiredCSS("splitView.css");
     this.element.classList.add("split-view");
 
     this._mainView = new WebInspector.VBox();
     this._mainElement = this._mainView.element;
     this._mainElement.className = "split-view-contents scroll-target split-view-main vbox"; // Override
 
     this._sidebarView = new WebInspector.VBox();
     this._sidebarElement = this._sidebarView.element;
     this._sidebarElement.className = "split-view-contents scroll-target split-view-sidebar vbox"; // Override
 
@@ skipping 825 matching lines @@
         this._showHideSidebarButton.state = sidebarHidden ? "show" : "hide";
         this._showHideSidebarButton.element.classList.toggle("top-sidebar-show-hide-button", !this.isVertical() && !this.isSidebarSecond());
         this._showHideSidebarButton.element.classList.toggle("right-sidebar-show-hide-button", this.isVertical() && this.isSidebarSecond());
         this._showHideSidebarButton.element.classList.toggle("bottom-sidebar-show-hide-button", !this.isVertical() && this.isSidebarSecond());
         this._showHideSidebarButton.element.classList.toggle("left-sidebar-show-hide-button", this.isVertical() && !this.isSidebarSecond());
         this._showHideSidebarButton.title = sidebarHidden ? WebInspector.UIString("Show %s", this._showHideSidebarButtonTitle) : WebInspector.UIString("Hide %s", this._showHideSidebarButtonTitle);
     },
 
     __proto__: WebInspector.View.prototype
 }