DevTools: [CSS] remove getAllStylesheets method from protocol

Source/devtools/front_end/CSSStyleModel.js

 /*
  * Copyright (C) 2010 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 153 matching lines @@
         {
             if (error)
                 callback(null, null);
             else
                 callback(cssFamilyName, fonts);
         }
         CSSAgent.getPlatformFontsForNode(nodeId, platformFontsCallback);
     },
 
     /**
+     * @return {!Array.<!WebInspector.CSSStyleSheetHeader>}
+     */
+    allStyleSheets: function()
+    {
+        return Object.values(this._styleSheetIdToHeader);
+    },
+
+    /**
      * @param {!DOMAgent.NodeId} nodeId
      * @param {function(?WebInspector.CSSStyleDeclaration, ?WebInspector.CSSStyleDeclaration)} userCallback
      */
     getInlineStylesAsync: function(nodeId, userCallback)
     {
         /**
          * @param {function(?WebInspector.CSSStyleDeclaration, ?WebInspector.CSSStyleDeclaration)} userCallback
          * @param {?Protocol.Error} error
          * @param {?CSSAgent.CSSStyle=} inlinePayload
          * @param {?CSSAgent.CSSStyle=} attributesStylePayload
@@ skipping 1645 matching lines @@
             for (var i = 0; i < callbacks.length; ++i)
                 callbacks[i](computedStyle);
         }
     }
 }
 
 /**
  * @type {!WebInspector.CSSStyleModel}
  */
 WebInspector.cssModel;