DevTools: Split creating inspector stylesheet and adding a new rule into stylesheet in protocol.

Source/devtools/front_end/DOMAgent.js

 /*
  * Copyright (C) 2009, 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Joseph Pecoraro
  *
  * 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.
@@ skipping 31 matching lines @@
     this._isInShadowTree = isInShadowTree;
 
     this.id = payload.nodeId;
     domAgent._idToDOMNode[this.id] = this;
     this._nodeType = payload.nodeType;
     this._nodeName = payload.nodeName;
     this._localName = payload.localName;
     this._nodeValue = payload.nodeValue;
     this._pseudoType = payload.pseudoType;
     this._shadowRootType = payload.shadowRootType;
+    this._frameId = payload.frameId || null;
 
     this._shadowRoots = [];
 
     this._attributes = [];
     this._attributesMap = {};
     if (payload.attributes)
         this._setAttributesPayload(payload.attributes);
 
     this._userProperties = {};
     this._descendantUserPropertyCounters = {};
@@ skipping 406 matching lines @@
     /**
      * @param {!WebInspector.DOMNode} descendant
      * @return {boolean}
      */
     isDescendant: function(descendant)
     {
         return descendant !== null && descendant.isAncestor(this);
     },
 
     /**
+     * @return {?PageAgent.FrameId}
+     */
+    frameId: function()
+    {
+        var node = this;
+        while (!node._frameId && node.parentNode)
+            node = node.parentNode;
+        return node._frameId;
+    },
+
+    /**
      * @param {!Array.<string>} attrs
      * @return {boolean}
      */
     _setAttributesPayload: function(attrs)
     {
         var attributesChanged = !this._attributes || attrs.length !== this._attributes.length * 2;
         var oldAttributesMap = this._attributesMap || {};
 
         this._attributes = [];
         this._attributesMap = {};
@@ skipping 1143 matching lines @@
     setInspectModeEnabled: function(enabled, inspectShadowDOM, config, callback)
     {
         DOMAgent.setInspectModeEnabled(enabled, inspectShadowDOM, config, callback);
     }
 }
 
 /**
  * @type {!WebInspector.DOMAgent}
  */
 WebInspector.domAgent;