DevTools: remove the ComputedStyles -> Styles pane dependency.

third_party/WebKit/Source/devtools/front_end/elements/StylesSidebarPane.js

 /*
  * Copyright (C) 2007 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 224 matching lines @@
     },
 
     /**
      * @override
      * @return {!Promise.<?>}
      */
     doUpdate: function()
     {
         this._discardElementUnderMouse();
 
-        return this.fetchMatchedCascade()
+        return this._fetchMatchedCascade()
             .then(this._innerRebuildUpdate.bind(this));
     },
 
     _resetCache: function()
     {
-        delete this._matchedCascadePromise;
+        if (this.cssModel())
+            this.cssModel().discardCachedMatchedCascade();
     },
 
     /**
      * @return {!Promise.<?WebInspector.CSSMatchedStyles>}
      */
-    fetchMatchedCascade: function()
+    _fetchMatchedCascade: function()
     {
         var node = this.node();
-        if (!node)
+        if (!node || !this.cssModel())
             return Promise.resolve(/** @type {?WebInspector.CSSMatchedStyles} */(null));
-        if (!this._matchedCascadePromise)
-            this._matchedCascadePromise = this._matchedStylesForNode(node).then(validateStyles.bind(this));
-        return this._matchedCascadePromise;
+
+        return this.cssModel().cachedMatchedCascadeForNode(node).then(validateStyles.bind(this));
 
         /**
          * @param {?WebInspector.CSSMatchedStyles} matchedStyles
          * @return {?WebInspector.CSSMatchedStyles}
          * @this {WebInspector.StylesSidebarPane}
          */
         function validateStyles(matchedStyles)
         {
             return matchedStyles && matchedStyles.node() === this.node() ? matchedStyles : null;
         }
     },
 
     /**
-     * @param {!WebInspector.DOMNode} node
-     * @return {!Promise.<?WebInspector.CSSMatchedStyles>}
-     */
-    _matchedStylesForNode: function(node)
-    {
-        var cssModel = this.cssModel();
-        if (!cssModel)
-            return Promise.resolve(/** @type {?WebInspector.CSSMatchedStyles} */(null));
-        return cssModel.matchedStylesPromise(node.id)
-    },
-
-    /**
      * @param {boolean} editing
      */
     setEditingStyle: function(editing)
     {
         if (this._isEditingStyle === editing)
             return;
         this.element.classList.toggle("is-editing-style", editing);
         this._isEditingStyle = editing;
     },
 
@@ skipping 2865 matching lines @@
 
     /**
      * @override
      * @return {!WebInspector.ToolbarItem}
      */
     item: function()
     {
         return this._button;
     }
 }